www.maths4scotland.co.uk Higher Maths Strategies Click to start Quit Quit Back to start Maths4Scotland Higher Select topic – from which the questions are taken. The Straight Line Functions Circle Polynomials Differentiation Quadratic Theory Integration Compound Angles Sequences Wave Function Vectors Exponential & Log Function Back to start Quit Quit Maths4Scotland The Straight Line Higher www.maths4scotland.co.uk Higher Maths Strategies The Straight Line Click to start Quit Quit Back to start Maths4Scotland The Straight Line Higher The following questions are on The Straight Line Non-calculator questions will be indicated You will need a pencil, paper, ruler and rubber. Click to continue Quit Quit Back to start Maths4Scotland The Straight Line Higher Find the equation of the line which passes through the point (-1, 3) and is perpendicular to the line with equation 4 x y 1 0 Find gradient of given line: 4 x y 1 0 y 4 x 1 m 4 m Find gradient of perpendicular: Find equation: 1 4 1 y 3 x 1 4( y 3) x 1 4 y 12 4 x ( 1) 4 y x 13 0 Back to start Previous Quit Quit Next Hint Maths4Scotland The Straight Line Higher Find the equation of the straight line which is parallel to the line with equation 2 x 3 y 5 and which passes through the point (2, –1). Find gradient of given line: 2 3 3 y 2 x 5 y x 5 m Gradient of parallel line is same: Find equation: 2 y ( 1) 3 x2 m 2 3 2 3 2x 4 3y 3 3y 2x 1 Back to start Previous Quit Quit Next Hint Maths4Scotland The Straight Line Higher Find the size of the angle a° that the line joining the points A(0, -1) and B(33, 2) makes with the positive direction of the x-axis. Find gradient of the line: Use m tan m 2 (1) 3 3 3 0 3 3 1 3 1 tan 3 Use table of exact values tan 1 1 30 3 Back to start Previous Table of exact values Quit Quit Next Hint Maths4Scotland The Straight Line Higher A and B are the points (–3, –1) and (5, 5). Find the equation of a) the line AB. b) the perpendicular bisector of AB Find gradient of the AB: Find mid-point of AB m 3 4 Find equation of AB Gradient of AB (perp): (1,2) 4 y 3x 5 4 m 3 Use gradient and mid-point to obtain perpendicular bisector AB 3 y 4 x 13 Back to start Previous Quit Quit Next Hint Maths4Scotland The Straight Line Higher radians with the 3 y-axis, as shown in the diagram. The line AB makes an angle of Find the exact value of the gradient of AB. Find angle between AB and x-axis: Use m tan m tan 2 3 6 (x and y axes are perpendicular) 6 Use table of exact values 1 m 3 Back to start Previous Table of exact values Quit Quit Next Hint Maths4Scotland The Straight Line Higher A triangle ABC has vertices A(4, 3), B(6, 1) and C(–2, –3) as shown in the diagram. Find the equation of AM, the median from A. Find mid-point of BC: (2, 1) Find gradient of median AM m2 Find equation of median AM y 2x 5 Back to start Previous Quit Quit Next Hint Maths4Scotland The Straight Line Higher P(–4, 5), Q(–2, –2) and R(4, 1) are the vertices of triangle PQR as shown in the diagram. Find the equation of PS, the altitude from P. Find gradient of QR: 1 m 2 Find gradient of PS (perpendicular to QR) m 2 y 2x 3 0 Find equation of altitude PS Back to start Previous Quit Quit Next Hint Maths4Scotland The Straight Line Higher The lines y 2 x 4 and x y 13 make angles of a and b with the positive direction of the x-axis, as shown in the diagram. a) Find the values of a and b b) Hence find the acute angle between the two given lines. Find gradient of y 2x 4 m2 Find a° tan a 2 a 63 Find gradient of x y 13 m 1 Find b° tan b 1 b 135 Find supplement of b Angle between two lines 180 135 45 Use angle sum triangle = 180° 72° Back to start Previous Quit Quit Next Hint Maths4Scotland The Straight Line Higher Triangle ABC has vertices A(–1, 6), B(–3, –2) and C(5, 2) Find: a) the equation of the line p, the median from C of triangle ABC. b) the equation of the line q, the perpendicular bisector of BC. c) the co-ordinates of the point of intersection of the lines p and q. Find mid-point of AB Find equation of p Find mid-point of BC Find gradient of q (-2, 2) Find gradient of p m0 y2 (1, 0) Find gradient of BC m 2 Find equation of q Solve p and q simultaneously for intersection 1 2 y 2x 2 m (0, 2) Back to start Previous Quit Quit Next Hint Maths4Scotland The Straight Line Higher Triangle ABC has vertices A(2, 2), B(12, 2) and C(8, 6). a) Write down the equation of l1, the perpendicular bisector of AB b) Find the equation of l2, the perpendicular bisector of AC. c) Find the point of intersection of lines l1 and l2 d) Hence find the equation of the circle passing through A, B and C. Mid-point AB 7, 2 Find mid-point AC (5, 4) Gradient AC perp. 3 m 2 Point of intersection (7, 1) Find radius (intersection to A) Equation of circle: Previous x7 2 m Find gradient of AC 3 2 y 3x 23 Equ. of perp. bisector AC Perpendicular bisector AB This is the centre of circle r 26 x 7 y 1 26 2 2 Quit Quit Back to start Next Hint Maths4Scotland The Straight Line Higher A triangle ABC has vertices A(–4, 1), B(12,3) and C(7, –7). a) Find the equation of the median CM. b) Find the equation of the altitude AD. c) Find the co-ordinates of the point of intersection of CM and AD Mid-point AB 4, 2 Gradient CM (median) y 3 x 14 Equation of median CM Gradient BC Equation of AD m 3 m2 Gradient of perpendicular AD m 2y x 2 0 Solve simultaneously for point of intersection (6, -4) Back to start Previous 1 2 Quit Quit Next Hint Maths4Scotland The Straight Line Higher A triangle ABC has vertices A(–3, –3), B(–1, 1) and C(7,–3). a) Show that the triangle ABC is right angled at B. b) The medians AD and BE intersect at M. i) Find the equations of AD and BE. ii) Hence find the co-ordinates of M. m2 Gradient AB Product of gradients 2 Gradient BC 1 1 2 1 m 2 Hence AB is perpendicular to BC, so B = 90° Mid-point BC 3, 1 Gradient of median AD Mid-point AC 2, 3 Gradient of median BE 1 3 4 m 3 m Solve simultaneously for M, point of intersection Equation AD 3y x 6 0 Equation AD 3y 4x 1 0 5 1, 3 Back to start Previous Quit Quit Next Hint Maths4Scotland The Straight Line Higher You have completed all 12 questions in this presentation Back to start Previous Quit Quit Back to start Higher Maths Graphs & Functions Strategies Click to start Quit Quit Back to start Maths4Scotland Graphs & Functions Higher The following questions are on Graphs & Functons Non-calculator questions will be indicated You will need a pencil, paper, ruler and rubber. Click to continue Quit Quit Back to start Maths4Scotland Graphs & Functions Higher The diagram shows the graph of a function f. f has a minimum turning point at (0, -3) and a point of inflexion at (-4, 2). a) sketch the graph of y = f(-x). y = 2f(-x) b) On the same diagram, sketch the graph of y = 2f(-x) a) y Reflect across the y axis y = f(-x) 4 2 -1 b) 3 Now scale by 2 in the y direction 4 x -3 -6 Previous Quit Quit Back to start Next Hint Maths4Scotland Graphs & Functions Higher The diagram shows a sketch of part of the graph of a trigonometric function whose equation is of the form y a sin(bx ) c Determine the values of a, b and c a is the amplitude: 1 2a a=4 b is the number of waves in 2 1 in 2 in 2 b=2 c is where the wave is centred vertically c=1 Back to start Previous Quit Quit Next Hint Maths4Scotland Functions f ( x) Graphs & Functions Higher 1 and g ( x) 2 x 3 are defined on suitable domains. x4 a) Find an expression for h(x) where h(x) = f(g(x)). b) Write down any restrictions on the domain of h. a) f ( g ( x)) f (2 x 3) b) 2 x 1 0 x 1 2x 3 4 h( x ) 1 2x 1 1 2 Back to start Previous Quit Quit Next Hint Maths4Scotland Graphs & Functions 2 in the form ( x a) b a) Express f ( x) x 4 x 5 b) On the same diagram sketch 2 c) i) the graph of ii) the graph of (2, 9) y f ( x) y=f(x) y 10 f ( x) b) 5 Find the range of values of x for which 10 f ( x) Higher is positive y= 10 - f(x) (2, 1) a) ( x 2)2 4 5 ( x 2)2 4 5 (2, -1) ( x 2)2 1 -5 c) Solve: 10 ( x 2)2 1 0 ( x 2)2 9 ( x 2) 3 y= -f(x) x 1 or 5 Back to start 10 - f(x) is positive for -1 < x < 5 Previous Quit Quit Next Hint Maths4Scotland Graphs & Functions Higher The graph of a function f intersects the x-axis at (–a, 0) and (e, 0) as shown. There is a point of inflexion at (0, b) and a maximum turning point at (c, d). Sketch the graph of the derived function f m is + m is + m is - f(x) Previous Quit Quit Back to start Next Hint Maths4Scotland Graphs & Functions Higher Functions f and g are defined on suitable domains by f ( x) sin( x) and g ( x ) 2 x a) Find expressions for: i) f ( g ( x)) ii) g ( f ( x)) b) Solve 2 f ( g ( x)) g ( f ( x)) for 0 x 360 a) f ( g ( x)) f (2 x) sin 2x b) 2sin 2x 2sin x sin 2 x sin x 0 2sin x cos x sin x 0 sin x 0 Previous or g ( f ( x)) g (sin x) 2sin x cos x 1 2 Quit sin x(2 cos x 1) 0 x 0, 180, 360 x 60, 300 Quit Back to start Next Hint Maths4Scotland Graphs & Functions Higher The diagram shows the graphs of two quadratic functions y f ( x) and y g ( x) Both graphs have a minimum turning point at (3, 2). Sketch the graph of y f ( x) and on the same diagram sketch the graph of y g ( x ) y=f(x) y=g(x) Back to start Previous Quit Quit Next Hint Maths4Scotland Graphs & Functions Higher Functions f ( x) sin x, g ( x) cos x and h( x) x 4 are defined on a suitable set of real numbers. a) Find expressions for g (h( x)) i) ii) f ( h( x )) b) f (h( x)) 1 2 sin x 1 2 cos x i) Show that ii) Find a similar expression for g (h( x)) and hence solve the equation f (h( x)) g (h( x)) 1 for 0 x 2 a) f (h( x)) f ( x ) b) sin( x ) sin x cos 4 sin( x ) g (h( x)) cos( x ) 4 4 4 sin 4 cos x 4 Now use exact values Repeat for ii) equation reduces to Previous 2 sin x 1 2 Quit sin x Quit 2 1 2 2 x 3 4 , 4 Back to start Next Hint Maths4Scotland Graphs & Functions Higher A sketch of the graph of y = f(x) where f ( x) x3 6 x 2 9 x is shown. The graph has a maximum at A and a minimum at B(3, 0) a) Find the co-ordinates of the turning point at A. b) Hence, sketch the graph of g ( x) f ( x 2) 4 Indicate the co-ordinates of the turning points. There is no need to calculate the co-ordinates of the points of intersection with the axes. c) Write down the range of values of k for which g(x) = k has 3 real roots. a) Differentiate f ( x) 3x 2 12 x 9 when x = 1 y4 t.p. at A is: for SP, f(x) = 0 (1, 4) moved 2 units to the left, and 4 units up b) Graph is c) For 3 real roots, line y = k has to cut graph at 3 points from the graph, k 4 Previous x 1 or x 3 t.p.’s are: (3, 0) (1, 4) (1, 4) (1, 8) Back to start Quit Quit Next Hint Maths4Scotland f ( x) 3 x a) Find 3 x g ( x) , and 3 3 x , x3 p(q( x)) x0 find p( x) f ( g ( x)) f b) Higher p( x) where p( x) f ( g ( x)) b) If q ( x) a) Graphs & Functions p 3 3 x 3 x 3 3 1 3 x 3 3 x 9 3(3 x) 3 x 3 x 3 in its simplest form. p ( q ( x )) 3 3 x 3 x 3 x 3( x 1) x 9 3 3 3 x 3 x 3x 3 x 3 x 3 x Back to start Previous Quit Quit Next Hint Maths4Scotland Graphs & Functions Higher Part of the graph of y f ( x) is shown in the diagram. On separate diagrams sketch the graph of a) y f ( x 1) b) y 2 f ( x) Indicate on each graph the images of O, A, B, C, and D. a) b) graph moves to the left 1 unit graph is reflected in the x axis graph is then scaled 2 units in the y direction Back to start Previous Quit Quit Next Hint Maths4Scotland Graphs & Functions Higher Functions f and g are defined on the set of real numbers by f ( x) x 1 and g ( x) x 2 a) Find formulae for i) ii) g ( f ( x)) f ( g ( x)) b) The function h is defined by h( x) f ( g ( x)) g ( f ( x)) Show that h( x) 2 x 2 2 x and sketch the graph of h. c) Find the area enclosed between this graph and the x-axis. a) f ( g ( x)) f ( x 2 ) x 2 1 b) h( x) x 2 1 x 1 c) 2 g ( f ( x)) g ( x 1) x 1 h( x) x 2 1 x 2 2 x 1 Graph cuts x axis at 0 and 1 Area Previous 1 3 unit Now evaluate 1 0 2 2 x2 2 x 2 x2 2 x dx Back to start 2 Quit Quit Next Hint Maths4Scotland Graphs & Functions Higher The functions f and g are defined on a suitable domain by f ( x) x 2 1 and g ( x) x 2 2 a) Find an expression for f ( g ( x)) b) Factorise f ( g ( x)) a) f ( g ( x)) f ( x 2) x 2 1 b) Difference of 2 squares 2 Simplify 2 2 x 2 x 2 1 2 2 1 x 2 3 x 2 1 Back to start Previous Quit Quit Next Hint Maths4Scotland Graphs & Functions Higher You have completed all 13 questions in this section Back to start Previous Quit Quit Maths4Scotland Sequences Higher www.maths4scotland.co.uk Higher Maths Strategies Sequences Click to start Quit Quit Back to start Maths4Scotland Sequences Higher The following questions are on Sequences Non-calculator questions will be indicated You will need a pencil, paper, ruler and rubber. Click to continue Quit Quit Back to start Maths4Scotland Sequences Higher A recurrence relation is defined by un 1 pun q where -1 < p < -1 and u0 = 12 a) If u1 = 15 and u2 = 16 find the values of p and q b) Find the limit of this recurrence relation as n Put u1 into recurrence relation 15 12 p q ..... (1) Put u2 into recurrence relation 16 15 p q ..... (2) Solve simultaneously: Hence p Previous 1 3p p 1 3 substitute into (1) q 11 1 and q 11 3 State limit condition Use formula (2) – (1) c L 1 m -1 < p < 1, so a limit L exists L Quit 11 1 1 3 Limit = 16½ Back to start Quit Next Hint Maths4Scotland Sequences Higher A man decides to plant a number of fast-growing trees as a boundary between his property and the property of his neighbour. He has been warned however by the local garden centre, that during any year, the trees are expected to increase in height by 0.5 metres. In response to this warning, he decides to trim 20% off the height of the trees at the start of any year. (a) If he adopts the “20% pruning policy”, to what height will he expect the trees to grow in the long run. (b) His neighbour is concerned that the trees are growing at an alarming rate and wants assurance that the trees will grow no taller than 2 metres. What is the minimum percentage that the trees will need to be trimmed each year so as to meet this condition. un1 0.8un 0.5 Construct a recurrence relation -1 < 0.8 < 1, so a limit L exists State limit condition Use formula L c 1 m L 0.5 1 0.8 Use formula again L c 1 m 2 0.5 1 m Previous un = height at the start of year Quit Limit = 2.5 metres m = 0.75 Minimum prune = 25% Back to start Quit Next Hint Maths4Scotland Sequences Higher On the first day of March, a bank loans a man £2500 at a fixed rate of interest of 1.5% per month. This interest is added on the last day of each month and is calculated on the amount due on the first day of the month. He agrees to make repayments on the first day of each subsequent month. Each repayment is £300 except for the smaller final amount which will pay off the loan. a) The amount that he owes at the start of each month is taken to be the amount still owing just after the monthly repayment has been made. Let un and un+1 and represent the amounts that he owes at the starts of two successive months. Write down a recurrence relation involving un and un+1 b) Find the date and amount of the final payment. Construct a recurrence relation un1 1.015un 300 u0 = 2500 Calculate each term in the recurrence relation 1 Mar 1 Apr 1 May 1 Jun 1 Jul Previous u0 = 2500.00 u1 = 2237.50 u2 = 1971.06 u3 = 1700.62 u4 = 1426.14 1 Aug 1 Sept 1 Oct 1 Nov 1 Dec Quit u5 = 1147.53 u6 = 864.74 u7 = 577.71 u8 = 286.38 Final payment £290.68 Quit Back to start Next Hint Maths4Scotland Sequences Higher Two sequences are generated by the recurrence relations un1 aun 10 and vn 1 a 2vn 16 The two sequences approach the same limit as n . Determine the value of a and evaluate the limit. L Use formula for each sequence L Sequence 1 Equate the two limits Simplify Solve 10 1 a 10 16 1 a 1 a2 5a 3 a 1 0 Previous L Sequence 2 10a 2 16a 6 0 Deduction c 1 m 16 1 a2 Cross multiply 5a 2 8a 3 0 hence a 1 3 Since limit exists a 1, so a 5 Quit or a 3 5 Limit = 25 Quit 10 1 a 2 16(1 a) Back to start Next Hint Maths4Scotland Sequences Higher Two sequences are defined by the recurrence relations un 1 0.2un p, u0 1 and vn 1 0.6vn q, v0 1 If both sequences have the same limit, express p in terms of q. L Use formula for each sequence Sequence 1 L p 1 0.2 p L Sequence 2 p q 0.8 0.4 Equate the two limits Rearrange c 1 m 0.6q 0.4 q 1 0.6 Cross multiply p 0.4 p 0.6q 3q 2 Back to start Previous Quit Quit Next Hint Maths4Scotland Sequences Higher Two sequences are defined by these recurrence relations un1 3un 0.4 with u0 1 vn1 0.3vn 4 with v0 1 a) Explain why only one of these sequences approaches a limit as n b) Find algebraically the exact value of the limit. c) For the other sequence find i) the smallest value of n for which the nth term exceeds 1000, and ii) the value of that term. Requirement for a limit First sequence has no limit since 3 is not between –1 and 1 2nd sequence has a limit since –1 < 0.3 < 1 L Sequence 2 List terms of 1st sequence 4 1 0.3 u0 = 1 u1 = 2.6 u2 = 7.4 L 4 0.7 u3 = 21.8 u4 = 65 u5 = 194.6 Limit 40 5 5 7 7 u6 = 583.4 u7 = 1749.8 Smallest value of n is 8; value of 8th term = 1749.8 Previous Quit Quit Back to start Next Hint Maths4Scotland Sequences Higher You have completed all 6 questions in this presentation Back to start Previous Quit Quit Maths4Scotland Differentiation Higher www.maths4scotland.co.uk Differentiation Higher Mathematics Next Back to start Quit Quit Maths4Scotland Differentiate Differentiation f ( x) x Straight line form Differentiate Higher 2 x2 1 2 f ( x) x 2 x 2 f ( x) x 1 2 1 2 4 x 3 Back to start Back Quit Quit Next Hint Maths4Scotland Differentiate Differentiation Higher y 2 x3 7 x 2 4 x 4 y 6 x 2 14 x 4 Back to start Back Quit Quit Next Hint Maths4Scotland Differentiate Differentiation y 2 sin x 6 Higher Chain Rule dy 2 cos x 1 6 dx Simplify dy 2 cos x 6 dx Back to start Back Quit Quit Next Hint Maths4Scotland Differentiate multiply out Differentiate Differentiation Higher 3 A a (8 a) 4 3 A 6a a 2 4 A 6 3 a 2 Back to start Back Quit Quit Next Hint Maths4Scotland Differentiate Chain Rule Simplify Differentiation Higher 1 3 2 f ( x) (8 x ) 1 2 f ( x) (8 x3 ) (2 x 2 ) 1 2 2 3 f ( x) x (8 x ) 1 2 Back to start Back Quit Quit Next Hint Maths4Scotland Differentiate Differentiation Higher 16 y x , x0 x 1 2 Straight line form y x 16 x Differentiate 3 dy 1 8x 2 dx Back to start Back Quit Quit Next Hint Maths4Scotland Differentiate Differentiation Higher 3 3 2 16 A( x) x 2 x Multiply out A( x) 3 3 2 3 3 16 x 2 2 x 3 3 2 x 24 3x 1 2 Straight line form A( x) Differentiate A( x) 3 3x 24 3x 2 Back to start Back Quit Quit Next Hint Maths4Scotland Differentiate Differentiation f ( x) 5 x 4 Chain Rule f ( x) Simplify f ( x) 1 2 1 2 5x 4 5 2 Higher 5x 4 1 2 5 1 2 Back to start Back Quit Quit Next Hint Maths4Scotland Differentiate Differentiation Higher 16 2 A( x) 240 x x 3 32 A( x) 240 x 3 Back to start Back Quit Quit Next Hint Maths4Scotland Differentiate Differentiation Higher f ( x) 3x 2 (2 x 1) Multiply out f ( x) 6 x 3 3 x 2 Differentiate f ( x) 18 x 2 6 x Back to start Back Quit Quit Next Hint Maths4Scotland Differentiate Chain Rule Simplify Differentiation Higher f ( x) cos2 x sin 2 x f ( x) 2 cos x sin x 2 sin x cos x f ( x) 4 cos x sin x Back to start Back Quit Quit Next Hint Maths4Scotland Quadratic Theory Higher Higher Maths Quadratic Theory Strategies Click to start Quit Quit Back to start Maths4Scotland Quadratic Theory Higher The following questions are on Quadratic Theory Non-calculator questions will be indicated You will need a pencil, paper, ruler and rubber. Click to continue Quit Quit Back to start Maths4Scotland Quadratic Theory Higher Show that the line with equation y 2 x 1 does not intersect the parabola with equation y x 2 3x 4 Put two equations equal Use discriminant Show discriminant < 0 No real roots Back to start Previous Quit Quit Next Hint Maths4Scotland a) Write Quadratic Theory x a f ( x) x 6 x 11 in the form 2 b) Hence or otherwise sketch the graph of a) f ( x) ( x 3)2 2 b) This is graph of y x2 minimum t.p. at (-3, 2) Higher 2 b y f ( x) moved 3 places to left and 2 units up. y-intercept at (0, 11) Back to start Previous Quit Quit Next Hint Maths4Scotland Quadratic Theory Show that the equation Higher (1 2k ) x 2 5kx 2k 0 has real roots for all integer values of k Use discriminant a (1 2k ) b 5k c 2k b2 4ac 25k 2 4 (1 2k ) 2k 9k 2 8k 25k 2 8k 16k 2 Consider when this is greater than or equal to zero Sketch graph cuts x axis at k 0 and k Hence equation has real roots for all integer k Previous Quit Quit 8 9 Back to start Next Hint Maths4Scotland Quadratic Theory Higher The diagram shows a sketch of a parabola passing through (–1, 0), (0, p) and (p, 0). a) Show that the equation of the parabola is y p ( p 1) x x 2 b) For what value of p will the line y x p be a tangent to this curve? a) y k ( x 1)( x p) Use point (0, p) to find k p pk k 1 y ( x 1)( x p) y p p 1 x x2 y x 2 px x p b) Simultaneous equations 0 p 2 x x2 p k (0 1)(0 p) x p p p 1 x x 2 Discriminant = 0 for tangency p 2 Back to start Previous Quit Quit Next Hint Maths4Scotland Given Quadratic Theory f ( x) x 2 x 8 , express f ( x ) in the form 2 Higher x a 2 b f ( x) ( x 1)2 10 Back to start Previous Quit Quit Next Hint Maths4Scotland Quadratic Theory Higher For what value of k does the equation x 2 5x (k 6) 0 have equal roots? Discriminant a 1 b 5 c k 6 b2 4ac 25 4(k 6) For equal roots discriminant = 0 0 25 4k 24 4k 1 1 k 4 Back to start Previous Quit Quit Next Hint Maths4Scotland Quadratic Theory Higher You have completed all 6 questions in this section Back to start Previous Quit Quit Maths4Scotland Integration Higher www.maths4scotland.co.uk Integration Higher Mathematics Next Back to start Quit Quit Maths4Scotland Integrate x Integration 2 Higher 4 x 3 dx 3 2 x 4x 3x c 3 2 Integrate term by term 1 3 2 x 2 x 3x c 3 simplify Back to start Back Quit Quit Next Hint Maths4Scotland Find Integration Higher 3cos x dx 3sin x c Back to start Back Quit Quit Next Hint Maths4Scotland Integrate Integration Higher (3x 1)( x 5) dx 2 3 x 14 x 5 dx Multiply out brackets 3x3 14 x 2 5x c 3 2 Integrate term by term x 7 x 5x c 3 simplify 2 Back to start Back Quit Quit Next Hint Maths4Scotland Find Integration Higher 2sin d 2cos c Back to start Back Quit Quit Next Hint Maths4Scotland Integrate Integration Higher (5 3 x) 2 dx (5 3x) c 3 3 3 Standard Integral (from Chain Rule) 1 3 (5 3 x) 9 c Back to start Back Quit Quit Next Hint Maths4Scotland Integration Find p, given Higher p x dx 42 1 p x 1 2 dx 42 1 2 3 p3 p3 2 3 2 42 64 p 2 x 42 3 1 3 2 p3 8 p3 2 3 3 2 p 2 (1) 3 3 2 2 126 p 2 Back to start Back Quit Quit 42 Next Hint Maths4Scotland Evaluate Integration 2 1 dx 2 x Straight line form Higher x 2 dx 1 x 1 21 11 1 1 2 1 2 1 2 2 Back to start Back Quit Quit Next Hint Maths4Scotland Find Integration 1 Higher Use standard Integral (from chain rule) (2 x 3) dx 6 0 1 (2 3)7 (0 3)7 14 14 (2 x 3) 7 2 0 7 57 37 14 14 5580.36 156.21 5424 Back to start Back Quit Quit Next (4sf) Hint Maths4Scotland Find Integration Higher 1 3sin x cos x dx 2 Integrate term by term 1 3cos x sin x c 2 Back to start Back Quit Quit Next Hint Maths4Scotland Integrate Integration 2 x 3 dx x Straight line form 2 3 3 2 Higher 1 2 x 2 x dx 2 2x x c 2 3 2 3 3 2 x x 2 c Back to start Back Quit Quit Next Hint Maths4Scotland Integrate Integration 1 x dx x 3 Straight line form 4 1 2 x x 1 c 4 2 Back Higher x x 3 1 4 1 2 dx 1 2 x4 2x c Back to start Quit Quit Next Hint Maths4Scotland Integrate Integration x x 3 1 2 Higher x 5x dx x 3 5x x 1 2 Straight line form dx 2 7 x 7 2 x 5 2 10 x 3 1 2 5x dx 3 2 c Back to start Back Quit Quit Next Hint Maths4Scotland Integrate 1 2 Integration Higher 3 2 4x x dx 2 x 1 2 2x x dx Split into separate fractions 2x 4x 4 3 x 3 2 1 2 1 4 x 3 2 2x 1 2 x c 2 Back to start Back Quit Quit dx Next Hint Maths4Scotland Find 2 Integration 2 x 1 3 Higher Use standard Integral (from chain rule) dx 1 2 x 1 4 2 4 54 34 8 8 4 14 2 14 4 2 4 2 2 1 68 Back to start Back Quit Quit Next Hint Maths4Scotland Find Integration Higher sin 2 x cos 3 x dx 4 1 1 cos 2 x sin 3 x 2 3 4 c Back to start Back Quit Quit Next Hint Maths4Scotland Find Integration Higher 2 sin t dt 7 2 cos t c 7 Back to start Back Quit Quit Next Hint Maths4Scotland Integration Integrate 1 0 dx 3x 1 Straight line form 1 2 1 3x 1 1 2 dx 0 2 3 1 3x 1 0 2 2 4 1 3 3 Back Higher 2 3 3 x 1 1 3 2 2 3 1 3 4 2 3 3 1 2 1 0 0 1 2 3 Back to start Quit Quit Next Hint Maths4Scotland Integration Higher 1 2 a 2(4 t ) , 0 t 4 Given the acceleration a is: If it starts at rest, find an expression for the velocity v where dv 2(4 t ) dt 1 2 4 v 3 4 0 3 4 Back v 4t 3 c 3 c 2(4 t ) 3 2 3 1 2 c Starts at rest, so v = 0, when t = 0 32 0 c 3 32 c 3 Quit Quit a dv dt 3 4 v (4 t ) 2 c 3 4 0 3 4 3 2 4 3 3 v (4 t ) Back to start Next c Hint 32 3 Maths4Scotland Integration dy 3sin(2 x) dx A curve for which 3 3 2 5 , 12 3 3 2 3 cos(2 3 5 )c 12 3 3 c 2 2 3 c 4 3 2 3 y cos(2 x) 3 3 c 4 3 4 Back to start Back 3 3 2 5 cos( ) c 6 4 3 3 3 c 4 4 passes through the point 5 , 12 y cos(2 x) c Find y in terms of x. Use the point Higher Quit Quit Next Hint Maths4Scotland Integrate Integration 2 2 x 2 x 2 x 2 dx, x 0 Multiply out brackets Split into separate fractions Higher x4 4 2 dx 2 x x x3 4 x 1 c 3 1 x4 4 dx 2 x 1 3 x 2 4 x 2 dx 4 x c x 3 Back to start Back Quit Quit Next Hint Maths4Scotland Integration f ( x) sin(3x) y f ( x) If f ( x) 1 7 6 c passes through the point 9 , 1 express y in terms of x. 1 cos(3x) c 3 1 cos 3 3 9 Higher c Use the point 1 1 cos 3 3 1 3 y cos(3 x) c 9 , 1 1 1 1 3 2 7 6 Back to start Back Quit Quit c Next Hint Maths4Scotland Integrate Integration 1 dx 2 (7 3 x) Higher Straight line form (7 3 x) 1 c 1 3 2 (7 3 x) dx 1 (7 3x) 1 c 3 Back to start Back Quit Quit Next Hint Maths4Scotland The graph of If y g ( x) dy 1 1 3 x 2 dx x 4 dy 1 3 2 x x dx 4 Integration passes through the point (1, 2). express y in terms of x. x 4 x 1 1 y xc 4 1 4 1 2 4 x 1 1 y xc 4 x 4 Evaluate c Higher simplify 4 1 1 1 c 4 1 4 Use the point 1 1 Hint y x x3 x Back4 to c3 1 4 4 start Back Quit Quit Next Maths4Scotland Integrate x2 x x 3 2 3 2 3 2 Integration x2 5 dx x x 5 x 5x 1 2 3 2 1 2 dx Higher Straight line form c 1 2 x 5x 2 3 3 2 3 2 x 10 x x2 5 x 3 2 dx 1 2 c Back to start Back Quit Quit dx Next Hint Maths4Scotland A curve for which Integration dy 6 x2 2 x dx Higher passes through the point (–1, 2). Express y in terms of x. 6 x3 2 x 2 y c 3 2 Use the point y 2 x3 x 2 c 2 2(1)3 (1)2 c c5 Hint y 2 x3 x 2 5 Back to start Back Quit Quit Next Maths4Scotland Evaluate 2 1 Integration 2 2 1 x dx x 2 4 1 2 1 5 2 x2 x 1 2 dx x 4 2 x x 2 dx 1 1 x5 x 2 x 1 5 1 32 5 2 1 Cannot use standard integral So multiply out Higher 64 10 40 10 1 5 25 2 2 20 10 2 10 1 2 1 5 1 5 82 10 12 1 1 8 15 Back to start Back Quit Quit Next Hint Maths4Scotland Evaluate Integration Higher x dx Straight line form 4 2 x 3 1 2 3 1 2 dx 1 1 3 2 x 4 4 3 2 4 3 4 2 x 3 3 1 3 1 16 2 3 3 14 3 Hint 4 Back to start Back Quit Quit Next 2 3 Maths4Scotland Evaluate Integration 0 (2 x 3) 2 Higher Use standard Integral (from chain rule) dx 3 0 (2 x 3) 3 2 3 3 27 27 6 6 (2(0) 3)3 (2(3) 3)3 6 6 27 27 6 6 54 6 9 Back to start Back Quit Quit Next Hint Maths4Scotland Integration y f ( x) The curve f ( x) cos 2 x f ( x) 1 1 passes through the point 1 sin 2 x 2 c ,1 12 Find f(x) 1 sin 2 2 12 1 1 2 2 Higher c use the given point 1 c c 3 4 1 sin 2 6 ,1 12 c sin 1 6 2 1 2 f ( x) sin 2 x Back to start Back Quit Quit Next 3 4 Hint Maths4Scotland Integrate Integration Higher (6 x 2 x cos x) dx 6 x3 x 2 sin x c 3 2 Integrate term by term Back to start Back Quit Quit Next Hint Maths4Scotland Integrate Integration Higher 3x 4 x dx 3 3x 4 4 x 2 c 4 2 Integrate term by term 3 4 x 2x c 4 2 Back to start Back Quit Quit Next Hint Maths4Scotland Integration 1 0 Evaluate 1 3x 3 3 2 2 9 1 3x 3 2 Back 1 0 1 3x dx 1 2 dx 1 0 1 3 2 1 3x 2 9 0 2 1 3(1) 9 16 2 9 9 Higher 3 2 9 1 3(0) 14 9 2 9 3 1 2 4 9 3 Quit 1 3 5 9 Back to start Quit 1 1 3x 0 3 Next Hint Maths4Scotland Compound Angles Higher www.maths4scotland.co.uk Higher Maths Strategies Compound Angles Click to start Quit Quit Back to start Maths4Scotland Compound Angles Higher The following questions are on Compound Angles Non-calculator questions will be indicated You will need a pencil, paper, ruler and rubber. Click to continue Quit Quit Back to start Maths4Scotland Compound Angles Higher This presentation is split into two parts Using Compound angle formula for Exact values Solving equations Choose by clicking on the appropriate button Back to start Quit Quit Maths4Scotland Compound Angles Higher A is the point (8, 4). The line OA is inclined at an angle p radians to the x-axis a) Find the exact values of: i) sin (2p) ii) cos (2p) The line OB is inclined at an angle 2p radians to the x-axis. b) Write down the exact value of the gradient of OB. Draw triangle 80 Pythagoras 4 p 8 8 sin p 80 4 8 2 80 80 cos p Write down values for cos p and sin p Expand sin (2p) sin 2 p 2sin p cos p Expand cos (2p) cos 2 p cos p sin p Use m = tan (2p) tan 2 p Previous 2 2 sin 2 p cos 2 p Quit 8 80 2 4 80 4 3 4 5 5 3 Quit 2 4 80 64 4 80 5 64 16 3 80 5 Back to start Next Hint Maths4Scotland Compound Angles Higher In triangle ABC show that the exact value of sin(a b) is Use Pythagoras Substitute values Simplify 10 2 AC 2 CB 10 Write down values for sin a, cos a, sin b, cos b Expand sin (a + b) 2 5 sin a 1 2 cos a 1 2 sin b 1 10 cos b 3 10 sin(a b) sin a cos b cos a sin b sin(a b) sin(a b) 3 20 1 20 1 3 2 10 4 20 1 1 2 10 4 4 2 45 2 5 5 Back to start Previous Quit Quit Next Hint Maths4Scotland Compound Angles Using triangle PQR, as shown, find the exact value of cos 2x 11 PR 11 Use Pythagoras Write down values for cos x and sin x 2 cos x 11 7 sin x 11 Expand cos 2x cos 2 x cos 2 x sin 2 x Substitute values cos 2x Simplify Previous Higher cos 2 x 2 11 4 7 11 11 Quit 2 7 11 3 11 Quit 2 Back to start Next Hint Maths4Scotland Compound Angles Higher On the co-ordinate diagram shown, A is the point (6, 8) and B is the point (12, -5). Angle AOC = p and angle COB = q Find the exact value of sin (p + q). Mark up triangles Use Pythagoras OA 10 Write down values for sin p, cos p, sin q, cos q 10 6 12 OB 13 sin p 8 , 10 cos p 6 , 10 sin q 5 , 13 sin ( p q) sin p cos q cos p sin q Substitute values sin ( p q) Previous sin ( p q) 96 130 30 130 Quit 5 13 Expand sin (p + q) Simplify 8 8 12 10 13 12 13 6 5 10 13 126 130 Quit cos q 63 65 Back to start Next Hint Maths4Scotland Compound Angles A and B are acute angles such that tan A Find the exact value of a) sin 2A b) cos 2A Draw triangles c) and tan B sin A sin 2 A 2sin A cos A Expand cos 2A cos 2 A cos A sin A Substitute Previous . 5 13 3 A 5 B 4 12 Hypotenuses are 5 and 13 respectively Expand sin 2A 2 Expand sin (2A + B) 5 12 sin(2 A B ) Use Pythagoras Write down sin A, cos A, sin B, cos B 3 4 Higher 2 3 , 5 cos A 4 , 5 sin B 3 5 sin 2 A 2 cos 2A 2 4 5 4 3 5 5 5 , 13 cos B 24 25 2 16 9 25 25 12 13 7 25 sin 2 A B sin 2 A cos B cos 2 A sin B sin 2 A B 24 12 7 5 323 25 13 25 13 325 Quit Quit Back to start Next Hint Maths4Scotland Compound Angles If x° is an acute angle such that tan x 4 3 Higher 5 4 3 3 sin( x 30) is show that the exact value of 10 4 x 3 Draw triangle Use Pythagoras Write down sin x and cos x Expand sin (x + 30) Hypotenuse is 5 sin x 4 , 5 cos x 3 5 sin( x 30) sin x cos 30 cos x sin 30 Substitute sin( x 30) 4 3 3 1 5 2 5 2 Simplify sin( x 30) 4 3 3 10 10 4 3 3 10 Back to start Previous Table of exact values Quit Quit Next Hint Maths4Scotland Compound Angles Higher The diagram shows two right angled triangles ABD and BCD with AB = 7 cm, BC = 4 cm and CD = 3 cm. Angle DBC = x° and angle ABD is y°. 20 6 6 Show that the exact value of cos( x y ) is 35 24 5 BD 5, AD 24 Use Pythagoras Write down sin x, cos x, sin y, cos y. Expand cos (x + y) sin x 3 , 5 cos x 4 , 5 sin y 24 , 7 cos y 5 7 cos( x y ) cos x cos y sin x sin y 4 5 3 24 5 7 5 7 Substitute cos( x y ) Simplify 20 3 4 6 20 6 6 20 3 24 cos( x y ) 35 35 Back to 35 35 start Previous Quit Quit Next Hint Maths4Scotland Compound Angles Higher The framework of a child’s swing has dimensions as shown in the diagram. Find the exact value of sin x° Draw triangle h 5 Use Pythagoras Draw in perpendicular 3 Use fact that sin x = sin ( ½ x + ½ x) sin sin Write down sin ½ x and cos ½ x Substitute Simplify sin x x 2 2 sin x sin x 2 x x 2 2 Expand sin ( ½ x + ½ x) 2 3 2 2 3 , cos x x cos 2 2 Table of exact values x 2 2 5 3 x 2 sin cos 3 4 x 2 x 2 2sin cos x 2 5 3 4 5 9 Previous x x 2 h5 Back to start Quit Quit Next Hint Maths4Scotland Given that tan Compound Angles 11 , 0 3 2 find the exact value of sin 2 Draw triangle Use Pythagoras Write down values for cos a and sin a 20 11 a hypotenuse 3 cos a 20 20 3 11 sin a 20 Expand sin 2a sin 2a 2 sin a cos a Substitute values sin 2a 2 Simplify 6 11 sin 2a 20 Previous Higher 11 3 20 20 Quit Quit 3 11 10 Back to start Next Hint Maths4Scotland Compound Angles Higher Find algebraically the exact value of sin sin 120 cos( 150) Expand sin ( +120) sin 120 sin cos120 cos sin120 Expand cos ( +150) cos 150 cos cos150 sin sin150 Use table of exact values Simplify cos 150 cos 30 sin 120 sin 150 sin 60 sin sin . Combine and substitute 1 2 3 2 cos 120 cos 60 sin sin 1 2 3 cos 2 cos . cos . sin . 1 2 3 2 3 cos 2 Table of exact values Quit Quit 3 2 1 2 sin 1 2 0 Previous sin 30 3 2 1 2 Back to start Next Hint Maths4Scotland If cos a) sin 2 Compound Angles 4 , 0 5 2 b) Draw triangle Find sin 4 Previous 5 3 Use Pythagoras 4 Opposite side = 3 4 cos 5 3 sin 5 3 4 24 2 5 5 25 sin 2 2 sin cos Expand sin 4 (4 = 2 + 2) Expand cos 2 find the exact value of sin 4 Write down values for cos and sin Expand sin 2 Higher sin 4 2 sin 2 cos 2 cos 2 cos sin 2 24 7 sin 4 2 25 25 Quit 2 336 625 Quit 16 9 7 25 25 25 Back to start Next Hint Maths4Scotland Compound Angles For acute angles P and Q sin P 12 and 13 sin Q Show that the exact value of sin ( P Q) Draw triangles Use Pythagoras Write down sin P, cos P, sin Q, cos Q Expand sin (P + Q) 3 5 13 63 65 5 12 P 3 Q 5 4 Adjacent sides are 5 and 4 respectively sin P 12 , 13 cos P 5 , 13 sin Q 3 , 5 cos Q 4 5 Back to start Hint sin P Q sin P cos Q cos P sin Q Substitute sin P Q 12 4 5 3 13 5 13 5 Simplify sin P Q 48 15 65 65 Previous Higher Quit Quit 63 65 Next Maths4Scotland Compound Angles Higher You have completed all 12 questions in this section Using Compound angle formula for Solving Equations Next Back to start Previous Quit Quit Back to start Maths4Scotland Compound Angles Higher Using Compound angle formula for Solving Equations Continue Back to start Quit Quit Maths4Scotland Compound Angles Higher Solve the equation 3cos(2 x) 10cos( x) 1 0 for 0 ≤ x ≤ correct to 2 decimal places Replace cos 2x with Substitute Simplify cos 2 x 2 cos 2 x 1 3 2 cos x 1 10 cos x 1 0 2 Determine quadrants 6 cos x 10 cos x 4 0 2 S A T C 3cos 2 x 5cos x 2 0 Factorise Hence 3cos x 1 cos x 2 0 cos x 1 3 cos x 2 Discard Find acute x Previous acute x 1.23 rad Quit x 1.23 or x 1.23 rads x 5.05 rads 2 1.23 Back to start Quit Next rads Hint Maths4Scotland Compound Angles Higher The diagram shows the graph of a cosine function from 0 to . a) State the equation of the graph. b) The line with equation y = -3 intersects this graph at points A and B. Find the co-ordinates of B. Equation y 2 cos 2 x Determine quadrants 2cos 2 x 3 Solve simultaneously cos 2x Rearrange Check range 0 x Find acute 2x Deduce 2x acute 2x 2x Table of exact values T C x 5 7 or 12 12 B 6 Previous A 3 2 0 2 x 2 6 or 6 6 S 6 rads 6 6 Quit Quit is B 7 12 , 3 Back to start Next Hint Maths4Scotland Compound Angles Higher Functions f and g are defined on suitable domains by f(x) = sin (x) and g(x) = 2x a) Find expressions for: i) f(g(x)) ii) g(f(x)) Determine x b) Solve 2 f(g(x)) = g(f(x)) for 0 x 360° 1st expression 2nd expression Form equation Replace sin 2x f ( g ( x)) f (2 x) sin 2 x cos x g ( f ( x)) g (sin x) 2sin x 2sin 2x 2sin x sin 2 x sin x 2sin x cos x sin x Common factor 1 2 acute x 60 S A T C Determine quadrants x 60, 300 2sin x cos x sin x 0 Rearrange Hence sin x 0 x 0, 360 x 0, 60, 300, 360 sin x 2cos x 1 0 sin x 0 or 2 cos x 1 0 cos x Previous Table of exact values Quit 1 2 Quit Back to start Next Hint Maths4Scotland Compound Angles Functions f ( x) sin x, g ( x) cos x a) Find expressions for b) i) 2nd expression expression Simplify h( x ) x 4 are defined on a suitable set of real numbers i) f(h(x)) ii) g(h(x)) 1 1 sin x cos x ii) Find a similar expression for g(h(x)) 2 2 Hence solve the equation f (h( x)) g (h( x)) 1 for 0 x 2 Show that iii) 1st and Higher 1st f (h( x)) g (h( x)) g x cos x f (h( x)) f x sin x 4 4 4 4 Rearrange: 4 4 f (h( x)) sin x cos cos x sin expr. 1 1 sin x 2 2 Use exact values f (h( x)) Similarly for 2nd expr. g (h( x)) cos x cos sin x sin g (h( x)) Form Eqn. 1 2 acute x cos x 4 4 cos x 1 sin x 2 f (h( x)) g (h( x)) 1 Previous Table of exact values Quit 2 2 Simplifies to Quit acute Determine quadrants x 3 4 , sin x 4 sin x 1 2 2 x 2 1 2 2 2 4 S A T C Back to start Next Hint Maths4Scotland a) b) Compound Angles Higher Solve the equation sin 2x - cos x = 0 in the interval 0 x 180° The diagram shows parts of two trigonometric graphs, y = sin 2x and y = cos x. Use your solutions in (a) to write down the co-ordinates of the point P. Replace sin 2x 2sin x cos x cos x 0 Common factor cos x 2sin x 1 0 Hence cos x 0 Determine x or Solutions for where graphs cross x 30, 90, 150 2sin x 1 0 sin x 1 2 cos x 0 x 90, ( 270 out of range) sin x 1 2 acute x 30 S A Determine quadrants for sin x Previous Coords, P Table of exact values C Quit y cos150 Find y value y x 30, 150 T x 150 By inspection (P) Quit P 150, 3 2 Back to start Next 3 2 Hint Maths4Scotland Solve the equation Compound Angles 3cos(2 x) cos( x) 1 for 0 ≤ x ≤ 360° cos 2 x 2 cos 2 x 1 Replace cos 2x with Determine quadrants 3 2 cos x 1 cos x 1 2 Substitute Simplify 6 cos 2 x cos x 2 0 Factorise 3cos x 2 2cos x 1 0 cos x Hence Find acute x acute 2 3 x 48 cos x acute Higher 1 2 x 60 cos x Table of exact values Quit Quit cos x 1 2 acute x 48 acute x 60 S A S A T C x 132 x 228 Solutions are: x= 60°, 132°, 228° and 300° Previous 2 3 T C x 60 x 300 Back to start Next Hint Maths4Scotland Compound Angles Solve the equation 2sin 2 x 6 1 Rearrange sin Find acute x Note range 2x 6 acute 2x 6 for 0 ≤ x ≤ 2 Determine quadrants 2x 6 and for range 6 0 x 2 0 2 x 4 S 0 2 x 2 for range 1 2 Higher 2x 6 6 2x 6 5 6 17 6 2 2 x 4 13 6 2x 6 A Solutions are: T x C 6 , 2 , 7 3 , 6 2 Back to start Previous Table of exact values Quit Quit Next Hint Maths4Scotland Compound Angles Higher a) Write the equation cos 2 + 8 cos + 9 = 0 in terms of cos and show that for cos it has equal roots. b) Show that there are no real roots for Replace cos 2 with cos 2 2 cos 2 1 Rearrange 2 cos 2 8cos 8 0 Divide by 2 cos 2 4 cos 4 0 Factorise Deduction Try to solve: cos 2 0 cos 2 No solution Hence there are no real solutions for cos 2 cos 2 0 Equal roots for cos Back to start Previous Quit Quit Next Hint Maths4Scotland Compound Angles Higher Solve algebraically, the equation sin 2x + sin x = 0, 0 x 360 Replace sin 2x 2sin x cos x sin x 0 Common factor sin x 2cos x 1 0 Hence S A T C sin x 0 or Determine x Determine quadrants for cos x 2cos x 1 0 cos x 1 2 x 120, 240 sin x 0 x 0, 360 1 2 cos x acute x 60 x = 0°, Previous Table of exact values Quit 120°, 240°, 360° Quit Back to start Next Hint Maths4Scotland Compound Angles Higher Find the exact solutions of 4sin2 x = 1, 0 x 2 Rearrange sin 2 x 1 4 Take square roots sin x 1 2 Find acute x acute x Determine quadrants for sin x S 6 + and – from the square root requires all 4 quadrants A T C 5 7 11 x , , , 6 6 6 6 Back to start Previous Table of exact values Quit Quit Next Hint Maths4Scotland Compound Angles Solve the equation cos 2x cos x 0 Replace cos 2x with cos 2 x 2 cos 2 x 1 for 0 ≤ x ≤ 360° Determine quadrants cos x 2 cos 2 x 1 cos x 0 Substitute Simplify 2 cos 2 x cos x 1 0 Factorise 2cos x 1 cos x 1 0 cos x Hence Find acute x acute 1 2 x 60 cos x 1 x 180 Table of exact values Quit 1 2 acute x 60 S A T C x 60 x 300 Solutions are: x= 60°, 180° and 300° Previous Higher Quit Back to start Next Hint Maths4Scotland Compound Angles cos2x 5cos x 2 0 Solve algebraically, the equation Replace cos 2x with Substitute cos 2 x 2 cos 2 x 1 Higher for 0 ≤ x ≤ 360° Determine quadrants 2 cos x 1 5cos x 2 0 2 cos x acute Simplify 2 cos 2 x 5cos x 3 0 Factorise 2cos x 1 cos x 3 0 Hence Find acute x cos x acute 1 2 x 60 S cos x 3 Discard above Table of exact values Quit Quit x 60 A T C x 60 x 300 Solutions are: x= 60° and 300° Previous 1 2 Back to start Next Hint Maths4Scotland Compound Angles Higher You have completed all 12 questions in this presentation Back to start Previous Quit Quit Back to start Maths4Scotland The Circle Higher www.maths4scotland.co.uk Higher Maths Strategies The Circle Click to start Quit Quit Back to start Maths4Scotland The Circle Higher The following questions are on The Circle Non-calculator questions will be indicated You will need a pencil, paper, ruler and rubber. Click to continue Quit Quit Back to start Maths4Scotland The Circle Higher Find the equation of the circle with centre (–3, 4) and passing through the origin. Find radius (distance formula): You know the centre: Write down equation: r 5 (3, 4) ( x 3)2 ( y 4)2 25 Back to start Previous Quit Quit Next Hint Maths4Scotland The Circle Explain why the equation x 2 does not represent a circle. Consider the 2 conditions Higher y2 2x 3 y 5 0 1. Coefficients of x2 and y2 must be the same. 2. Radius must be > 0 g 1, Calculate g and f: Evaluate Deduction: g f c 2 2 f (1) 2 g 2 f 2 c 0 so i.e. g 2 f 2 c 0 3 2 5 3 2 2 1 4 1 2 5 0 g 2 f 2 c not real Equation does not represent a circle Back to start Previous Quit Quit Next Hint Maths4Scotland The Circle Higher Find the equation of the circle which has P(–2, –1) and Q(4, 5) as the end points of a diameter. Q(4, 5) C Make a sketch P(-2, -1) (1, 2) Calculate mid-point for centre: Calculate radius CQ: Write down equation; r 18 x 1 y 2 18 2 2 Back to start Previous Quit Quit Next Hint Maths4Scotland The Circle Higher Find the equation of the tangent at the point (3, 4) on the circle x 2 y 2 2 x 4 y 15 0 Calculate centre of circle: P(3, 4) (1, 2) Make a sketch O(-1, 2) Calculate gradient of OP (radius to tangent) Gradient of tangent: m 2 Equation of tangent: y 2 x 10 m 1 2 Back to start Previous Quit Quit Next Hint Maths4Scotland The Circle Higher The point P(2, 3) lies on the circle ( x 1)2 ( y 1)2 13 Find the equation of the tangent at P. Find centre of circle: P(2, 3) (1, 1) Make a sketch O(-1, 1) Calculate gradient of radius to tangent Gradient of tangent: 3 m 2 Equation of tangent: 2 y 3 x 12 m 2 3 Back to start Previous Quit Quit Next Hint Maths4Scotland The Circle Higher O, A and B are the centres of the three circles shown in the diagram. The two outer circles are congruent, each touches the smallest circle. Circle centre A has equation x 12 2 y 5 25 2 The three centres lie on a parabola whose axis of symmetry is shown the by broken line through A. a) i) State coordinates of A and find length of line OA. ii) Hence find the equation of the circle with centre B. b) The equation of the parabola can be written in the form y px( x q ) A is centre of small circle A(12, 5) Find OA (Distance formula) Use symmetry, find B B(24, 0) Find radius of circle A from eqn. Find radius of circle B 13 5 8 Eqn. of B Points O, A, B lie on parabola – subst. A and B in turn 0 24 p (24 q) 5 12 p (12 q) Solve: Find p and q. 13 5 ( x 24) 2 y 2 64 p 5 , 144 q 24 Back to start Previous Quit Quit Next Hint Maths4Scotland The Circle Higher Circle P has equation x 2 y 2 8x 10 y 9 0 Circle Q has centre (–2, –1) and radius 22. a) i) Show that the radius of circle P is 42 ii) Hence show that circles P and Q touch. b) Find the equation of the tangent to circle Q at the point (–4, 1) c) The tangent in (b) intersects circle P in two points. Find the x co-ordinates of the points of intersection, expressing your answers in the form a b 3 Find centre of circle P: Find radius of circle :P: (4, 5) Find distance between centres 72 6 2 Gradient of radius of Q to tangent: Equation of tangent: m 1 Deduction: = sum of radii, so circles touch Gradient tangent at Q: m 1 y x5 2 2 Solve eqns. simultaneously x y 8 x 10 y 9 0 y x5 Previous 42 52 9 32 4 2 Quit Quit Soln: 22 3 Back to start Next Hint Maths4Scotland The Circle For what range of values of k does the equation represent a circle ? g 2k , Determine g, f and c: State condition g f c 0 2 2 5k 2 k 2 0 Simplify f k, Higher x 2 y 2 4kx 2ky k 2 0 c k 2 Put in values (2k )2 k 2 (k 2) 0 Need to see the position of the parabola Complete the square 1 5 5 k2 k 2 5k 1 5 k 10 1 10 2 2 Previous 1 2 100 195 100 Minimum value is 195 1 when k 100 10 This is positive, so graph is: Expression is positive for all k: So equation is a circle for all values of k. Quit Quit Back to start Next Hint Maths4Scotland The Circle For what range of values of c does the equation represent a circle ? Determine g, f and c: g 3, State condition g2 f 2 c 0 Simplify 94c 0 Re-arrange: Higher x2 y 2 6 x 4 y c 0 f 2, c? Put in values 32 (2)2 c 0 c 13 Back to start Previous Quit Quit Next Hint Maths4Scotland The Circle Higher The circle shown has equation ( x 3)2 ( y 2)2 25 Find the equation of the tangent at the point (6, 2). Calculate centre of circle: (3, 2) Calculate gradient of radius (to tangent) 4 m 3 3 4 Gradient of tangent: m Equation of tangent: 4 y 3 x 26 Back to start Previous Quit Quit Next Hint Maths4Scotland The Circle Higher When newspapers were printed by lithograph, the newsprint had to run over three rollers, illustrated in the diagram by 3 circles. The centres A, B and C of the three circles are collinear. The equations of the circumferences of the outer circles are ( x 12)2 ( y 15)2 25 and ( x 24)2 ( y 12)2 100 Find the equation of the central circle. Find centre and radius of Circle A (12, 15) Find centre and radius of Circle C (24, 12) Find diameter of circle B 45 (5 10) 30 Use proportion to find B 25 27 45 Previous (4, 3) r 5 25 r 10 15, Equation of B Quit 27 B 20 362 272 45 Find distance AB (distance formula) Centre of B (24, 12) (-12, -15) 36 so radius of B = 15 25 36 45 20 relative to C Back to x 4 y 3 225 start 2 Quit 2 Next Hint Maths4Scotland The Circle Higher You have completed all 11 questions in this presentation Back to start Previous Quit Quit Back to start Maths4Scotland Vectors Higher Higher Maths Vectors Strategies Click to start Quit Quit Back to start Maths4Scotland Vectors Higher The following questions are on Vectors Non-calculator questions will be indicated You will need a pencil, paper, ruler and rubber. Click to continue Quit Quit Back to start Maths4Scotland Vectors Higher The questions are in groups General vector questions (15) Points dividing lines in ratios Collinear points (8) Angles between vectors (5) Back to start Quit Quit Maths4Scotland Vectors Higher General Vector Questions Continue Back to start Quit Quit Maths4Scotland Vectors Higher Vectors u and v are defined by u 3i 2 j and v 2i 3 j 4k Determine whether or not u and v are perpendicular to each other. Is Scalar product = 0 3 u.v 2 0 u.v 3 2 2 3 0 4 u.v 0 2 3 4 u.v 6 6 0 Hence vectors are perpendicular Back to start Previous Quit Quit Next Hint Maths4Scotland Vectors For what value of t are the vectors u Put Scalar product = 0 t 2 3 Perpendicular u.v = 0 and v t u.v 2 3 u.v 2t 2 10 3t Higher 2 10 t perpendicular ? 2 10 t u.v 5t 20 0 5t 20 t4 Back to start Previous Quit Quit Next Hint Maths4Scotland Vectors Higher VABCD is a pyramid with rectangular base ABCD. The vectors AB, AD and AV are given by AB 8i 2 j 2k AD 2i 10 j 2k AV i 7 j 7k Express CV in component form. Ttriangle rule ACV AC CV AV Triangle rule ABC AB BC AC also CV AV AB AD Previous Re-arrange BC AD 1 8 2 CV 7 2 10 7 2 2 CV 9i 5 j 7k Quit CV AV AC 9 CV 5 7 Back to start Quit Next Hint Maths4Scotland Vectors Higher The diagram shows two vectors a and b, with | a | = 3 and | b | = 22. These vectors are inclined at an angle of 45° to each other. a) Evaluate i) a.a ii) b.b iii) a.b b) Another vector p is defined by p 2a 3b Evaluate p.p and hence write down | p |. i) a a a a cos 0 3 3 1 9 iii) a b a b cos 45 3 2 2 b) p p 2a 3b 2a 3b ii) bb 2 2 2 2 1 6 2 4a.a 12a.b 9b.b 36 72 72 180 Since p.p = p2 p 180 6 5 Previous Quit 8 Quit Back to start Next Hint Maths4Scotland Vectors Vectors p, q and r are defined by p i j - k , a) Express p q 2r in component form b) Calculate p.r c) Find |r| Higher q i 4k , i j - k i 4k 2 4i 3 j and r 4i 3 j 8i 5 j - 5 k a) p q 2r b) p.r i j - k . 4i 3 j p.r 1 4 1 (3) (1) 0 p.r 1 c) r 42 (3)2 r 16 9 r 5 Back to start Previous Quit Quit Next Hint Maths4Scotland Vectors Higher The diagram shows a point P with co-ordinates (4, 2, 6) and two points S and T which lie on the x-axis. If P is 7 units from S and 7 units from T, find the co-ordinates of S and T. Use distance formula S ( a, 0, 0) PS 2 49 (4 a)2 22 62 a 43 T (b, 0, 0) 49 (4 a)2 40 9 (4 a)2 a 7 or a 1 hence there are 2 points on the x axis that are 7 units from P S (1, 0, 0) and i.e. S and T T (7, 0, 0) Back to start Previous Quit Quit Next Hint Maths4Scotland Vectors Higher The position vectors of the points P and Q are p = –i +3j+4k and q = 7 i – j + 5 k respectively. a) Express PQ in component form. b) Find the length of PQ. a) b) PQ q - p PQ 7 1 1 - 3 5 4 PQ 82 (4) 2 12 PQ 64 16 1 8 4 1 81 8i 4 j k 9 Back to start Previous Quit Quit Next Hint Maths4Scotland Vectors Higher P PQR is an equilateral triangle of side 2 units. PQ a, PR b, and QR c Evaluate a.(b + c) and hence identify two vectors which are perpendicular. a b Diagram Q a.(b c ) a.b a.c a.b a b cos 60 60° 60° 60° R c a.b 2 2 1 2 a.b 2 NB for a.c vectors must point OUT of the vertex ( so angle is 120° ) 1 a.c 2 2 a.c a c cos120 2 Hence a.(b c ) 0 a.c 2 so, a is perpendicular to b + c Back to start Previous Table of Exact Values Quit Quit Next Hint Maths4Scotland Vectors Higher Calculate the length of the vector 2i – 3j + 3k Length 2 (3) 2 2 3 2 493 16 4 Back to start Previous Quit Quit Next Hint Maths4Scotland Vectors Find the value of k for which the vectors 1 2 1 1 0 2 1 4 3 k 1 Put Scalar product = 0 0 4 6 (k 1) Higher and 4 3 k 1 are perpendicular 0 2 k 1 k 3 Back to start Previous Quit Quit Next Hint Maths4Scotland Vectors Higher A is the point (2, –1, 4), B is (7, 1, 3) and C is (–6, 4, 2). If ABCD is a parallelogram, find the co-ordinates of D. AD BC c b D is the displacement hence d BC AD 2 13 1 3 4 1 Previous 6 7 4 1 2 3 BC 13 3 1 from A d 11 2 3 Quit Quit D 11, 2, 3 Back to start Next Hint Maths4Scotland If 3 u 3 3 and v 1 5 1 Vectors Higher write down the components of u + v and u – v Hence show that u + v and u – v are perpendicular. uv 2 8 2 u v . u v uv 2 4 8 2 2 4 4 2 4 look at scalar product u v . u v (2) (4) 8 (2) 2 4 8 16 8 Hence vectors are perpendicular Previous Quit Quit 0 Back to start Next Hint Maths4Scotland Vectors Higher The vectors a, b and c are defined as follows: a = 2i – k, b = i + 2j + k, c = –j + k a) Evaluate a.b + a.c b) From your answer to part (a), make a deduction about the vector b + c a) 2 1 a.b 0 2 1 1 a.c b) 2 0 0 1 1 1 a.b 2 0 1 a.b 1 a.c 0 0 1 a.c 1 a.b a.c 0 b + c is perpendicular to a Back to start Previous Quit Quit Next Hint Maths4Scotland Vectors Higher A is the point ( –3, 2, 4 ) and B is ( –1, 3, 2 ) Find: a) the components of AB b) the length of AB a) b) AB b a AB 1 3 3 2 2 4 AB 22 12 (2)2 AB 2 1 2 AB 4 1 4 AB 3 AB 9 Back to start Previous Quit Quit Next Hint Maths4Scotland Vectors Higher In the square based pyramid, all the eight edges are of length 3 units. AV p, AD q, AB r , Evaluate p.(q + r) Triangular faces are all equilateral p.(q r ) p.q p.r p.q p q cos 60 p.r p r cos60 1 2 p.(q r ) 4 4 Previous 1 2 Table of Exact Values p.q 1 3 3 2 p.r 1 3 3 2 p.(q r ) 9 Quit Quit p.q 4 p.q 1 2 1 4 2 Back to start Next Hint Maths4Scotland Vectors Higher You have completed all 15 questions in this section Back to start Previous Quit Quit Maths4Scotland Vectors Higher Points dividing lines in ratios Collinear Points Continue Back to start Quit Quit Maths4Scotland Vectors Higher A and B are the points (-1, -3, 2) and (2, -1, 1) respectively. B and C are the points of trisection of AD. That is, AB = BC = CD. Find the coordinates of D AB 1 AD 3 3AB AD 3b 3a d a d 2 1 3 1 2 3 1 2 Previous 3 b a d a d 3b 2a d 8 3 1 Quit D(8, 3, 1) Back to start Quit Next Hint Maths4Scotland Vectors Higher The point Q divides the line joining P(–1, –1, 0) to R(5, 2 –3) in the ratio 2:1. Find the co-ordinates of Q. R Diagram PQ 2 QR 1 3q P 1 q p 2r 2q PQ 2QR 5 1 2 2 1 3 0 2 Q 3q 2r p 1 9 q 3 3 6 Q(3, 1, 2) Back to start Previous Quit Quit Next Hint Maths4Scotland Vectors Higher a) Roadmakers look along the tops of a set of T-rods to ensure that straight sections of road are being created. Relative to suitable axes the top left corners of the T-rods are the points A(–8, –10, –2), B(–2, –1, 1) and C(6, 11, 5). Determine whether or not the section of road ABC has been built in a straight line. b) A further T-rod is placed such that D has co-ordinates (1, –4, 4). Show that DB is perpendicular to AB. a) AB b a AB b) and AB 6 2 9 3 3 3 1 AC 14 2 21 7 3 7 1 AC are scalar multiples, so are parallel. A is common. A, B, C are collinear Use scalar product AB.BD 6 3 9 . 3 3 3 AB.BD 18 27 9 0 Hence, DB is perpendicular to AB Previous Quit Quit Back to start Next Hint Maths4Scotland Vectors Higher VABCD is a pyramid with rectangular base ABCD. Relative to some appropriate axis, VA represents – 7i – 13j – 11k 6i + 6j – 6k AB represents 8i – 4j – 4k AD represents K divides BC in the ratio 1:3 Find VK in component form. VA AB VB VK VB KB VK VK KB VB 1 4 1 4 1 4 VK VA AB AD 7 6 8 1 13 6 4 11 6 4 4 Previous 1 4 KB CB DA AD VK Quit 1 8 18 Quit Back to start Next Hint Maths4Scotland Vectors Higher The line AB is divided into 3 equal parts by the points C and D, as shown. A and B have co-ordinates (3, –1, 2) and (9, 2, –4). a) Find the components of AB and AC b) Find the co-ordinates of C and D. a) b) AB b a AB 6 3 6 C is a displacement of AC from A similarly Previous d 5 2 0 1 0 2 2 1 AC AB 1 3 2 c 3 2 1 1 2 2 C (5, 0, 0) D(7, 1, 2) Back to start Quit Quit Next Hint Maths4Scotland Vectors Higher Relative to a suitable set of axes, the tops of three chimneys have co-ordinates given by A(1, 3, 2), B(2, –1, 4) and C(4, –9, 8). Show that A, B and C are collinear AB b a AB and AB 1 4 2 AC 3 1 12 3 4 6 2 AC are scalar multiples, so are parallel. A is common. A, B, C are collinear Back to start Previous Quit Quit Next Hint Maths4Scotland Vectors Higher A is the point (2, –5, 6), B is (6, –3, 4) and C is (12, 0, 1). Show that A, B and C are collinear and determine the ratio in which B divides AC AB b a AB and BC AB 2 BC 3 Previous AB 4 2 2 2 1 2 1 BC 6 2 3 3 1 3 1 are scalar multiples, so are parallel. B is common. A, B, C are collinear A 2 B 3 C B divides AB in ratio 2 : 3 Quit Quit Back to start Next Hint Maths4Scotland Vectors Higher Relative to the top of a hill, three gliders have positions given by R(–1, –8, –2), S(2, –5, 4) and T(3, –4, 6). Prove that R, S and T are collinear RS s r RS and RT RS 3 1 3 3 1 6 2 RT 4 1 4 4 1 8 2 are scalar multiples, so are parallel. R is common. R, S, T are collinear Back to start Previous Quit Quit Next Hint Maths4Scotland Vectors Higher You have completed all 8 questions in this section Back to start Previous Quit Quit Maths4Scotland Vectors Higher Angle between two vectors Continue Back to start Quit Quit Maths4Scotland Vectors Higher The diagram shows vectors a and b. If |a| = 5, |b| = 4 and a.(a + b) = 36 Find the size of the acute angle between a and b. cos a.b a b a.a a a 25 11 cos 5 4 Previous a.(a b) 36 a.a a.b 36 25 a.b 36 11 cos 20 56.6 1 Quit a.b 11 Back to start Quit Next Hint Maths4Scotland Vectors Higher The diagram shows a square based pyramid of height 8 units. Square OABC has a side length of 6 units. The co-ordinates of A and D are (6, 0, 0) and (3, 3, 8). C lies on the y-axis. a) Write down the co-ordinates of B b) Determine the components of DA and DB c) Calculate the size of angle ADB. a) c) B(6, 6, 0) cos AD.DB AD DB cos Previous 64 82 82 b) 3 DA 3 8 AD DB 3 DA 3 8 141.3 Quit 3 3 8 AD.DB 3 3 3 . 3 64 8 8 Back to start Quit Next Hint Maths4Scotland Vectors Higher A box in the shape of a cuboid designed with circles of different sizes on each face. The diagram shows three of the circles, where the origin represents one of the corners of the cuboid. The centres of the circles are A(6, 0, 7), B(0, 5, 6) and C(4, 5, 0) Find the size of angle ABC Vectors to point away from vertex 6 BA 5 1 4 BC 0 6 BA 36 25 1 62 cos 18 62 52 Previous BA.BC 24 0 6 18 BC 16 36 52 71.5 Quit Quit Back to start Next Hint Maths4Scotland Vectors Higher A cuboid measuring 11cm by 5 cm by 7 cm is placed centrally on top of another cuboid measuring 17 cm by 9 cm by 8 cm. Co-ordinate axes are taken as shown. a) The point A has co-ordinates (0, 9, 8) and C has co-ordinates (17, 0, 8). Write down the co-ordinates of B b) Calculate the size of angle ABC. a) B(3, 2, 15) b) 15 BC 2 7 BA.BC 45 14 49 10 BA 9 49 49 107 Previous 3 BA 7 7 BC 225 4 49 278 10 cos 278 107 Quit Quit 93.3 Back to start Next Hint Maths4Scotland Vectors Higher A triangle ABC has vertices A(2, –1, 3), B(3, 6, 5) and C(6, 6, –2). a) Find and AB AC b) Calculate the size of angle BAC. c) Hence find the area of the triangle. a) b) 1 AB b a 7 2 AB 12 7 2 22 54 cos c) 4 AC c a 7 5 43 0.6168 54 90 Area of ABC = Previous AC 90 AB. AC 4 49 10 43 cos1 0.6168 51.9 1 ab sin C 2 Quit 1 90 54 sin 51.9 2 Quit BAC = 51.9 27.43 unit 2 Back to start Next Hint Maths4Scotland Vectors Higher You have completed all 5 questions in this section Back to start Previous Quit Quit Maths4Scotland The Wave Function Higher www.maths4scotland.co.uk Higher Maths Strategies The Wave Function Click to start Quit Quit Back to start Maths4Scotland The Wave Function Higher The following questions are on The Wave Function Non-calculator questions will be indicated You will need a pencil, paper, ruler and rubber. Click to continue Quit Quit Back to start Maths4Scotland The Wave Function Higher Part of the graph of y = 2 sin x + 5 cos x is shown in the diagram. a) Express y = 2 sin x + 5 cos x in the form k sin (x + a) where k > 0 and 0 a 360 b) Find the coordinates of the minimum turning point P. Expand ksin(x + a): k sin( x a) k sin x cos a k cos x sin a Equate coefficients: k cos a 2 Square and add Dividing: k 2 2 2 52 tan a 5 2 k sin a 5 k 29 acute a 68 Put together: 2sin x 5cos x 29 sin( x 68) Minimum when: ( x 68) 270 x 202 P has coords. Previous (sin and cos are +) a 68 Back to start (202, 29) Quit a is in 1st quadrant Quit Next Hint a) b) Write sin x - cos x in the form k sin (x - a) stating the values of k and a where k > 0 and 0 a 2 Sketch the graph of sin x - cos x for 0 a 2 showing clearly the graph’s maximum and minimum values and where it cuts the x-axis and the y-axis. Expand ksin(x - a): k sin( x a) k sin x cos a k cos x sin a Equate coefficients: k cos a 1 k 2 12 12 Square and add tan a 1 Dividing: k 2 acute a a is in 1st quadrant 4 (sin and cos are +) 2 a 4 sin x cos x 2 sin( x ) Put together: 4 Sketch Graph max max at Previous k sin a 1 2 x 3 4 min min at Table of exact values 2 2 x Quit 7 4 k 2 Quit Back to start Next a 4 Hint Maths4Scotland The Wave Function Higher Express 8cos x 6sin x in the form k cos( x a) where k 0 and 0 a 360 Expand kcos(x + a): k cos( x a) k cos x cos a k sin x sin a Equate coefficients: k cos a 8 Square and add k 2 82 62 Dividing: Put together: tan a 6 8 k sin a 6 k 10 acute a 37 a is in 1st quadrant a 37 (sin and cos are +) 8cos x 6sin x 10 cos( x 37) Back to start Previous Quit Quit Next Hint Maths4Scotland The Wave Function Higher Find the maximum value of cos x sin x and the value of x for which it occurs in the interval 0 x 2. Express as Rcos(x - a): R cos( x a) R cos x cos a R sin x sin a Equate coefficients: R cos a 1 Square and add R 2 12 12 Dividing: Put together: Max value: tan a 1 acute R sin a 1 R 2 a a is in 4th quadrant 4 (sin is - and cos is +) 0, x cos x sin x 2 cos x 2 when Previous Table of exact values x Quit 7 4 a 7 4 7 4 Quit 7 4 Back to start Next Hint Maths4Scotland The Wave Function Higher Express 2sin x 5cos x in the form k sin( x ), 0 360 and k 0 Expand ksin(x - a): k sin( x a) k sin x cos a k cos x sin a Equate coefficients: k cos a 2 Square and add k 2 2 2 52 5 2 k sin a 5 k 29 a 68 a is in 1st quadrant Dividing: tan a Put together: 2cos x 5sin x 29 sin x 68 acute (sin and cos are both +) a 68 Back to start Previous Quit Quit Next Hint Maths4Scotland The Wave Function Higher The diagram shows an incomplete graph of y 3sin x , for 0 x 2 3 Find the coordinates of the maximum stationary point. Max for sine occurs (...) Coordinates of max s.p. 2 x , 5 6 Sine takes values between 1 and -1 Max value of sine function: Max value of function: 3 5 ,3 6 Back to start Previous Quit Quit Next Hint Maths4Scotland The Wave Function Higher f ( x) 2 cos x 3sin x a) Express f (x) in the form k cos( x ) b) Hence solve algebraically f ( x) 0.5 Expand kcos(x - a): k cos a 2 Square and add k 2 22 32 Put together: tan a x 56 82 Previous and 0 360 0 x 360 3 2 acute k sin a 3 k 13 a 56 a is in 1st quadrant (sin and cos are both + ) a 56 2cos x 3sin x 13 cos x 56 Solve equation. acute for k 0 k cos( x a) k cos x cos a k sin x sin a Equate coefficients: Dividing: where cos x 56 13 cos x 56 0.5 Cosine +, so 1st & 4th quadrants x 138 or x 334 Quit Quit 0.5 13 Back to start Next Hint Maths4Scotland The Wave Function Solve the simultaneous equations k sin x 5 where k > 0 and 0 x 360 k cos x 2 Higher Use tan A = sin A / cos A Divide tan x Find acute angle 5 2 acute Determine quadrant(s) x 68 Sine and cosine are both + in original equations Solution must be in 1st quadrant State solution x 68 Back to start Previous Quit Quit Next Hint Maths4Scotland The Wave Function Higher Solve the equation 2sin x 3cos x 2.5 in the interval 0 x 360. R cos( x a) R cos x cos a R sin x sin a Use Rcos(x - a): R cos a 3 Equate coefficients: R 2 22 3 Square and add tan a Dividing: Put together: x 146 46 x 192 or Previous acute R 13 a 34 a is in 2nd quadrant a 146 (sin + and cos - ) 2sin x 3cos x 13 cos x 146 Solve equation. acute 2 3 2 R sin a 2 x 460 cos x 146 13 cos x 146 2.5 2.5 13 Cosine +, so 1st & 4th quadrants (out of range, so subtract 360°) Quit x 100 Quit or x 192start Back to Next Hint Maths4Scotland The Wave Function Higher You have completed all 9 questions in this presentation Back to start Previous Quit Quit Back to start Maths4Scotland Logarithms & Exponential Higher www.maths4scotland.co.uk Higher Maths Logarithms & Exponential Next Quit Back to start Quit Maths4Scotland Logarithms & Exponential Higher Reminder All the questions on this topic will depend upon you knowing and being able to use, some very basic rules and facts. Click to show When you see this button click for more information Back to start Back Quit Quit Next Maths4Scotland Logarithms & Exponential Higher Three Rules of logs log a x log a y log a xy x log a x log a y log a y log a x p log a x p Back to start Back Quit Quit Next Maths4Scotland Logarithms & Exponential Higher Two special logarithms log a a 1 log a 1 0 Back to start Back Quit Quit Next Maths4Scotland Logarithms & Exponential Higher Relationship between log and exponential log a x y a x y Back to start Back Quit Quit Next Maths4Scotland Logarithms & Exponential Higher Graph of the exponential function Back to start Back Quit Quit Next Maths4Scotland Logarithms & Exponential Higher Graph of the logarithmic function Back to start Back Quit Quit Next Maths4Scotland Logarithms & Exponential Higher Related functions of y f ( x) y f ( x a) y f ( x a) y f ( x) y f ( x) y f ( x) a y f ( x) a Move graph left a Move graph right units a units Reflect in x axis Reflect in y axis Move graph up a units Move graph down a units Click to show Back to start Back Quit Quit Next Maths4Scotland Logarithms & Exponential Higher Calculator keys ln = log e log = log10 Back to start Back Quit Quit Next Maths4Scotland Logarithms & Exponential Higher Calculator keys loge 2.5 = log10 7.6 = ln 2 . 5 = = 0.916… log 7 . 6 = = 0.8808… Back to start Back Quit Quit Click to show Next Maths4Scotland Logarithms & Exponential Higher Solving exponential equations 2.4 3.1e x Use log ab = log a + log b log e 2.4 log e 3.1e x x log e 2.4 log e 3.1 log e e Use log ax = x log a loge 2.4 loge 3.1 x loge e Use loga a = 1 log e 2.4 log e 3.1 x Take loge both sides x log e 2.4 log e 3.1 0.25593... 0.26 (2dp) Back to start Back Quit Quit Next Show Maths4Scotland Logarithms & Exponential Higher Solving exponential equations 60 80e k log e 60 log e 80e k Take loge both sides log e 60 log e 80 log e e Use log ab = log a + log b k Use log ax = x log a loge 60 loge 80 k loge e Use loga a = 1 loge 60 loge 80 k k loge 80 loge 60 Back Quit 0.2876... 0.29 (2dp) Back to start Quit Next Show Maths4Scotland Logarithms & Exponential Higher Solving logarithmic equations log3 y 0.5 Change to exponential form 0.5 y 3 Change to exponential form y 3 1 2 1 3 1 2 1 3 y 0.577.... 0.58 (2dp) Back to start Back Quit Quit Next Show Maths4Scotland Logarithms & Exponential Higher 3loge (2e) 2log e (3e) A log e B log e C expressing your answer in the form Simplify where A, B and C are whole numbers. log e (2e) log e (3e) 3 2 8e3 log e 2 9e log e 8e3 log e 9e2 8e log e 9 loge 8 loge e loge 9 1 loge 8 log e 9 Back to start Back Quit Quit Next Show Maths4Scotland Simplify Logarithms & Exponential Higher log5 2 log5 50 log5 4 2 50 log 5 4 log 5 52 log5 25 2 2 log5 5 Back to start Back Quit Quit Next Show Maths4Scotland Find x if Logarithms & Exponential 4 log x 6 2 log x 4 1 64 log x 2 1 4 log x 64 log x 42 1 9 log x Higher 36 36 1 4 4 1 9 log x 81 1 1 x 81 x1 81 Back to start Back Quit Quit Next Show Maths4Scotland Given Logarithms & Exponential x log5 3 log5 4 Higher find algebraically the value of x. x log5 3 4 x log5 12 5x 12 log10 5x log10 12 log10 12 x log10 5 x log10 5 log10 12 x 1.5439.. x 1.54 (2 dp) Back to start Back Quit Quit Next Show Maths4Scotland Logarithms & Exponential Higher Find the x co-ordinate of the point where the graph of the curve with equation y log3 ( x 2) 1 intersects the x-axis. When y = 0 0 log3 ( x 2) 1 Re-arrange 1 log3 ( x 2) Exponential form Re-arrange 31 x 2 1 x 23 x2 1 3 Back to start Back Quit Quit Next Show Maths4Scotland Logarithms & Exponential Higher The graph illustrates the law y kx n If the straight line passes through A(0.5, 0) and B(0, 1). Find the values of k and n. log 5 y log 5 kx n Gradient log5 y log5 k n log5 x Y log5 k nX 1 0.5 y-intercept log5 k 1 k 5 n 2 (gradient) Back to start Back Quit Quit Next Show 1 Maths4Scotland Logarithms & Exponential Higher Before a forest fire was brought under control, the spread of fire was described by a law of the form A A0e kt where A0 is the area covered by the fire when it was first detected and A is the area covered by the fire t hours later. If it takes one and a half hours for the area of the forest fire to double, find the value of the constant k. 2 A0 A0 e k 1.5 loge 2 1.5k 2 ek 1.5 loge 2 1.5k loge e log e 2 k k 0.462.. 0.46 1.5 Back to start Back Quit Quit Next Show (2 dp) Maths4Scotland Logarithms & Exponential The results of an experiment Higher give rise to the graph shown. a) Write down the equation of the line in terms of P and Q. It is given that P log e p and Q log e q b) Show that p and q satisfy a relationship of the form p aqb stating the values of a and b. 0.6 Gradient Back loge p loge a b loge q y-intercept 1.8 P 0.6Q 1.8 log e p log e aq b P log e a bQ log e a 1.8 a e1.8 Quit Quit b 0.6 a 6.05 Back to start Next Show Maths4Scotland Logarithms & Exponential Higher The diagram shows part of the graph of y logb ( x a) Determine the values of a and b. . Use (7, 1) 1 logb (7 a) ...(1) Use (3, 0) 0 logb (3 a) ...(2) Hence, from (2) and from (1) Back 3 a 1 1 log b 5 Quit a 2 b5 Back to start Quit Next Show Maths4Scotland Logarithms & Exponential Higher The diagram shows a sketch of part of the graph of y log 2 ( x) a) State the values of a and b. b) Sketch the graph of a 1 y log 2 ( x 1) 3 b3 Graph moves 1 unit to the left and 3 units down Back to start Back Quit Quit Next Show Maths4Scotland Logarithms & Exponential a) i) Sketch the graph of Higher y a x 1, a 2 ii) On the same diagram, sketch the graph of y a x 1 , a 2 b) Prove that the graphs intersect at a point where the x-coordinate is a x 1 a x 1 1 log a a 1 1 a x 1 a x loga 1 log a a x log a a 1 x loga a 1 1 a x a 1 0 x log a a 1 x log a a 1 1 1 x log a a 1 Back to start Back Quit Quit Next Show Maths4Scotland Logarithms & Exponential Higher Part of the graph of y 5 log10 (2 x 10) is shown in the diagram. This graph crosses the x-axis at the point A and y 8 the straight line at the point B. Find algebraically the x co-ordinates of A and B. 8 5 log10 (2 x 10) 101.6 2 x 10 0 5 log10 (2 x 10) 8 1.6 log10 (2 x 10) log10 (2 x 10) 5 101.6 10 2x x 14.9 B (14.9, 8) 2 x 10 1 x 4.5 A (4.5, 0) Back to start Back Quit Quit Next Show Maths4Scotland Logarithms & Exponential Higher The diagram is a sketch of part of y ax , a 1 the graph of a) If (1, t) and (u, 1) lie on this curve, write down the values of t and u. b) Make a copy of this diagram and on it sketch the graph of y a 2x c) Find the co-ordinates of the point of intersection of y a 2x with the line a) ta c) y a 21 x 1 u 0 y a2 b) 2 1, a Back to start Back Quit Quit Next Show Maths4Scotland Logarithms & Exponential Higher The diagram shows part of the graph with equation y 3x y 42 and the straight line with equation These graphs intersect at P. Solve algebraically the equation 3x 42 and hence write down, correct to 3 decimal places, the co-ordinates of P. log10 3x log10 42 log10 42 x log10 3 x log10 3 log10 42 x 3.40217... P (3.402, 42) Back to start Back Quit Quit Next Show Maths4Scotland Higher Table of exact values sin cos tan 30° 45° 60° 6 1 2 4 3 1 2 1 2 3 2 3 2 1 3 1 1 2 3 Back to start Return Quit Quit Maths4Scotland Higher www.maths4scotland.co.uk © CPD 2004 Quit Quit Back to start Maths4Scotland Higher Sorry, This option is not yet available Back to start Quit Quit