Contents Formulae in other document but otherwise should be all covered... From additional mathematics for OCR book Algebra 1 Linear expressions Quadratic expressions Completing the square Simultaneous equations Contents Algebra 4 Binomial expansion Binomial distribution Geometry 1 Gradient of a line Different lines and Calculus 1 Introduction Gradient of a curve Differentiation Tangents and normals Stationary points and Higher Derivatives calculating distances Equation of a straight Algebra 2 Calculus 2 line Linear inequalities Circle Integration Quadratic Definite integrals Geometry 2 inequalities Area between curves Inequalities Algebraic fractions Linear programming Calculus 3 Expressions Motion in a straight containing a square Trigonometry 1 line root The Basics Constant Sine rule Algebra 3 acceleration Cosine rule Polynomials Velocity Trigonometry 2 Factor theorem Formulae (other Remainder theorem 3d work document) Linear expressions Quadratic expressions Completing the square Simultaneous equations Ex 1A, B & C Contents This is basically GCSE if not SAT revision When simplifying remember to: Collect like terms Remove brackets Factorise Find a common denominator when involving fractions When solving an equation remember to: Simplify Do the same on both sides so that it remains the same equation They sometimes ask to rearrange an expression in which case be careful to do so correctly Ex 1D Contents This is when the highest power is 2 It often involves expanding and factorising Before starting to solve a quadratic equation, make sure that all terms of the quadratic are on the left hand side of the equation There are 3 ways to solve a quadratic equation: Factorise 2. Completing the square 3. Using the Quadratic Formula 1. Remember that the formula is: You use this when you are in a calculator test and cannot factorise Ex 1E Contents Method: It is used Method: when you X²-8x=-3* Y = x²-8x +3* Take the coefficient cannot This can be of x-8 written as y=(xfactorise a Half it 4)²-13 quadratic -4 See Square the answer It is also previous +16 useful when example Add this to both sides and its sketching a Factorise where answer graph as it possible Therefore the Take the square root identifies the line of symmetry of both sides line of is x=4 and the Add the constant to symmetry and vertex is (4,-13) both sides the vertex Find the answer Ex 1F Contents This is when there is more than one variable ...by substitution Suitable for when y is the subject Take the expression for y from the equation and substitute it in the other equation – then solve as before ...by elimination Suitable for when y is not the subject or either equation Multiply the equations as so that when they are subtracted/added from the other they eliminate variables Substitute this into the first equation and thus solve Linear inequalities Quadratic in equalities Algebraic fractions Expressions containing a square root Ex 2A Contents Like simplifying linear expressions, you do the same to both sides However, remember to have the inequality sign the right way and whether it is equal to or not You may also be asked to show the answer on a number line In this case, remember that open circles at the end of the line show that the number is not included Closed circles mean the figure is included in your answer Both can be used in a single answer Ex 2B Contents There are two methods: Sketching a graph to show the answer Or drawing up a table showing the values of x But remember that if it has terms on both sides these must be collected to one side These quadratic inequalities will be able to be factorised Remember to be careful in reading and working the question especially when using a graph Ex 2C & D Algebraic fractions follow the same rules as the fractions in arithmetic The common denominator should be the lowest common multiple of the original denominators Contents Other than being asked to simplify an algebraic fraction you may be asked to solve an equation involving fractions This is done in the same way as before but also having to simplify fractions Remember that when you multiply a fraction you only multiply its numerator Ex 2E Contents It is often easier to use surds when working with square roots to get a more accurate answer than just working out the numerical value You should try to make the number that is under the square root sign as small as possible or as easy to work with as possible Rationalising the denominator is an important technique to be aware of Triangles Sine rule Cosine rule Contents Just remember the hyp, app and adj. And that θ is used for the angle The Trigonometric ratios are: Remember: sinθ (etc.) will give you the ratio -1 sin known side (etc.)will give you the angle side known X sinθ (etc.) will give you the side’s length Contents Sin is Opposite divided by Hypotenuse. Opposite is a helpful way of remembering it. S • skiving O • off H • homework Contents Tan is Opposite divided by Adjacent An easy way to remember is it doesn’t have the hyp and opp is always on top Opposite is a helpful way of remembering it. T O A Contents Cos is Adjacent divided by Hypotenuse Opposite is a helpful way of remembering it. C A H Contents It is an extension of Pythagoras’ theorem which allows it to be applied to any triangle AB = AC + BC - 2(AC)(BC) cos C c = b + a - 2ab cos c a = b + c - 2bc cos a b = a + c 2ac cos b OR cos A = b + c - a / 2bc Contents It is based on that fact that in any triangle the length of any edge is proportional to the sine of the angle opposite to that edge a / sin A = = b / sin B c / sin C Contents This formula (which is cyclic) is for finding the area of a triangle when the lengths of 2 edges are known and also the size of the angle between them Area ½ bc sin A = = ½ ab sin C ½ ca sin B = 3d work Contents Anti-clockwise is always positive Clockwise is negative Always go from the x axis Cosine and Sine are between -1 and 1 whereas Tangent is over 1 Silver Sin Cos Tan Sin Cos Tan + + Tea All Sin Cos Tan + + + Sin Cos + Tan Cups All Silver Tea Cups It is like have a circle of one unit 1 1 -1 -1 Contents It is really important to draw good diagrams There are two types: Representations of 3D objects True shape diagrams of 2D sections in a 3D object Contents The two main identities that need to be learnt: Introduction – Curves, Tangents, and Normals Gradient of a curve Differentiation Tangents and normals Stationary points and Higher Derivatives Contents Cord: joins two points on the curve Tangent: touches the curve at a point of contact Normal: perpendicular to the tangent at the point of contact The tangent to a curve can be considered as the limit position of a chord Curved line Contents As B gets closer to A we can say that B tends to A (written as BA) The gradient of the cord AB the gradient of the tangent at A E.g. y = x² A = (xA ,yA) B = (xB, yB) Mab = Yb - Ya Xb - Xa Xa Ya = (Xa)² Xb Yb = (Xb)² 2 4 3.5 12.25 5.5 2 4 3 9 5 2 4 2.5 6.25 4.5 2 4 2.25 5.0625 4.25 2 4 2.1 4.41 4.1 2 4 2.05 4.2025 4.05 2 4 2.001 4.004001 4.001 From the table, we can assume that the gradient of the tangent to the graph y = x² at A(2,4) is 4 Contents y = x² y = x³ X Gradient X Gradient 1 2 1 3 2 4 2 12 3 6 3 27 4 8 4 48 5 10 5 75 x 2x x 3x² y = x⁴ X Gradient 1 4 2 32 3 108 4 256 5 500 x 4x³ Contents The value of the gradient of the chord AB as B tends Note that ‘d’ has no independent meaning to A is called the and must never be differential coefficient of regarded as a factor. The y with respect to x or the d complete symbol dx derivative of y with means ‘the derivative respect to x. The limit is dy with respect to x of denoted by the symbol dx [previous expression]’ (read as ‘dy by dx’) dy We may also write The process of obtaining dx when y is a function of x the differential coefficient as f’(x) or y’ or derivative of a function is called differentiation. Contents Contents d e.g. dx d dx (x⁷) = 7x⁶ (xⁿ) = nxⁿ⁻¹ d dx d dx e.g. √x= (x^½) = ½x^-½ 1 = 2√x Contents y y=c 0 x Let y=c Graphically this is a horizontal straight line and its gradient is zero Therefore differentiating a constant will give you zero i.e. d dx (c) = 0 Contents d dx (axⁿ) = a d dx (xⁿ) = anxⁿ⁻¹ Where ‘a’ is a constant d i.e. dx (axⁿ) = anxⁿ⁻¹ For example: d dx (3x⁶) = 18x⁵ Contents We differentiate each term and then add or/and subtract the terms as necessary For example: d dx (x⁷ + 5x² - 3x + 4) = 7x⁶ + 10x - 3 Contents The gradient of the chord AB as it tends to the point A, is the value of the derivative at that point A. We can use this to find the equation of the tangent and/or of the normal to a curve at a given point Contents Q. Find the equation of the tangent and of the normal to the curve: y = x² + 3x – 10 at the point (1, -6) First differentiate the equation to give: d = 2x + 3 dx at x = 1 Thus: m=2X1+3=5 Using: y – y₁ = m(x – x₁) substitute the known values y + 6 = 5(x – 1) y = 5x – 5 – 6 y = 5x – 11 equation of tangent Then to find the equation of the normal: m = 5 so m¹ = -⅕ y + 6 = -⅕ (x-1) use previous method but using -⅕ instead of 5 5y + 30 = -x + 1 x + 5y + 29 = 0 equation of the normal Contents This is basically doing the second derivative This is just differentiating what you already have differentiated It can be used to find stationary points in increasing and decreasing functions Contents Increasing is from A to B and from C – represented with the + d y + + 0 - + A 0 B positive + - + + This means that dx is 0 - - - + + + C + x Decreasing is from B to C – represented with the This means that d is negative dx Stationary point are A, B and C – represented by the zero d This means that dx = 0 Contents This I where the gradient is zero They can be maximum points, minimum points, or points of inflection To find stationary points: Differentiate and find the value(s) of when this = 0 Substitute these values into the original equation to find y To find the nature of the stationary points work out the second derivative and then substitute the value(s) of x found before to decide if they are a min/max points or points of inflection Contents At point P dy dx dy dx dy dx =0 =0 =0 d²y dx² d²y dx² Maximum point <0 Minimum point >0 d²y d³y = 0 and ≠0 dx² dx³ (doesn’t change sign on either said of P) Point of inflection Remember to physically do and say each step in a question including saying if a certain point is a max., min. or point of inflection.