Scottish Higher Still Course www.mathsrevision.com Higher Still Level Exam 2002 Paper 2 Created by Graduate Bsc (Hons) MathsSci (Open) GIMA y 1. (a) Given the diagram opposite we have A(-1,6) Mid-point from AB is C(5,2) O ⎡ [ −1 + ( −3) ] , [ 6 + ( −2) ] ⎤ ( −2 , 2) ⎢ ⎥ 2 2 ⎣ ⎦ x B(-3,-2) Equation of the median line p from C is y = 2 (b) Gradient of BC mbc [ 2 − ( −2) ] 4 1 [ 5 − ( −3) ] 8 2 Gradient of bisector is -2 since mbc ⋅ mbisector −1 Midpoint of BC is ⎡ [ 5 + ( −3) ] , [ 2 + ( −2) ] ⎤ ( −1, 0) ⎢ ⎥ 2 2 ⎣ ⎦ Equation of bisector q is y−0 2x + y (c) −2( x − 1) 2 Intersection co-ordinates of p and q are −2x + 2 2 x=0 Co-ordinates are (0, 2) Page 1 of 9 Scottish Higher Still Course www.mathsrevision.com Higher Still Level Exam 2002 Paper 2 Created by Graduate Bsc (Hons) MathsSci (Open) GIMA 2. Given A (6, 0, 0) and D (3, 3, 8) (a) C is (0, 6, and 0) (b) → ⎯ DA → ⎯ → ⎯ → ⎯ DC + CO + OA → ⎯ DB ( 6 , 6 , 0) − ( 3 , 3 , 8) (c) ( −3 , 3 , −8) + ( 0 , −6 , 0) + ( 6 , 0 , 0) ( 3 , 3 , −8) Angle ADB Using the dot product rule we have cos ( ADB) cos ( ADB) angle ( ADB) ⎯ → →⎯ DA⋅ DB DA ⋅ DB 64 32 82 41 cos ( 3 , −3 , −8) ⋅ ( 3 , 3 , −8) ( 9 + 9 + 64) ⋅ ( 9 + 9 + 64) 32 ⎞ o ⎜ 41 38.7 ⎝ ⎠ − 1⎛ Page 2 of 9 ( 3 , −3 , −8) Scottish Higher Still Course www.mathsrevision.com Higher Still Level Exam 2002 Paper 2 Created by Graduate Bsc (Hons) MathsSci (Open) GIMA 3. Given y 2x − 7x + 4x + 4 (a) Max / Mini is given by 3 y y = f(x) 2 A o d y dx 0 d y dx 6x − 14x + 4 2 (2,0) 0 This factorises to give ( 3x − 1) ( 2x − 4) 0 x x 2 and 1 3 From the sketch it is clear that x (b) 2 is a minimum x and From the sketch clearly (x-2) is a factor. Using synthetic division we get 3 2 2x − 7x + 4x + 4 2 2x − 3x − 2 ( 2 ) ( x − 2) 2x − 3x − 2 ( 2x + 1) ( x − 2) Hence we have ( 2x + 1) ( x − 2) 2 Page 3 of 9 1 3 is a maximum x Scottish Higher Still Course www.mathsrevision.com Higher Still Level Exam 2002 Paper 2 Created by Graduate Bsc (Hons) MathsSci (Open) GIMA (c) The point A is ⎛ −1 , 0⎞ ⎜ 2 ⎝ ⎠ : x from part (b) 2x-1 = 0 Hence 3 2 2x − 7x + 4x + 4 < 0 4. x< for −1 2 From Information given we can write:Using the recurrence formula U n +1 = a ⋅U n + C We have U n +1 = U n + 0.5 − 0.2 ⋅ U n U n +1 = 0.8 ⋅ U n + 0.5 (a) Limiting value is found by L 0.8⋅ L + 0.5 rearranging we get (b) L 0.5 ( 1 − 0.8) 2.5metres To make sure they do not grow more than 2 metres we need:L 0.5 ( 1 − a) 2 rearranging we get a 0.75 Hence we need to trim the hedges by at least 25 % each year. Page 4 of 9 Scottish Higher Still Course www.mathsrevision.com Higher Still Level Exam 2002 Paper 2 Created by Graduate Bsc (Hons) MathsSci (Open) GIMA 5. Given the sketch and the equations:y (a) 2 1 + 10x − 2x y To get the points of intersection we have 2 1 + 10⋅ x − 2⋅ x 2 x − 5x 2 1 + 5⋅ x − x 0 x⋅ ( x − 5) x (b) 2 1 + 5x − x 0 0 and x 5 To find shaded area we have:5 ( 5 ( ) ( ) A ⌠ 2 2 ⎮ 1 + 10⋅ x − 2⋅ x − 1 + 5⋅ x − x dx ⌡0 A ⌠ 2 ⎮ −x − 5⋅ x dx ⌡0 A ) 2 ⎛ x3 x ⎞ ⎜ − − 5⋅ 2⎠ ⎝ 3 2 3 2 ⎛ 53 5 ⎞ ⎛ 0 0 ⎞ ⎜ − − 5⋅ − ⎜ − − 5⋅ 2 ⎠ ⎝ 3 2 ⎠ ⎝ 3 125 6 Page 5 of 9 Scottish Higher Still Course www.mathsrevision.com Higher Still Level Exam 2002 Paper 2 Created by Graduate Bsc (Hons) MathsSci (Open) GIMA 6. Given:For y π⎞ π x 6⎠ 3 π x 3 ⎛ π − π⎞ ⎝3 6⎠ 2⋅ sin ⎜ y ⎛ ⎝ 2⋅ sin ⎜ x − ⎛ π⎞ ⎝6⎠ 2⋅ sin ⎜ 1 ⎛π ⎞ ⎜ ,1 ⎝3 ⎠ Hence co-ordinates P is Value of gradient at x π is given by d y ⎜⎛ ⎞ 3 dx ⎝ 3 ⎠ π Using the chain rule we get d y dx ⎛ ⎝ 2⋅ cos ⎜ x − d ⎛ π⎞ y⎜ dx ⎝ 3 ⎠ π⎞ 6⎠ ⎛ π − π⎞ ⎝3 6⎠ 2⋅ cos ⎜ We have gradient ⎛ π⎞ ⎝6⎠ 2⋅ cos ⎜ 3 3 ⎛ π , 1⎞ ⎝3 ⎠ P⎜ Hence equation of the tangent is y−1 ⎛ ⎝ 3⋅ ⎜ x − π⎞ 3⎠ y ⎛ ⎝ 3⋅ x + ⎜ 1 − Page 6 of 9 π ⎞ 3⎠ Scottish Higher Still Course www.mathsrevision.com Higher Still Level Exam 2002 Paper 2 Created by Graduate Bsc (Hons) MathsSci (Open) GIMA 7. Given: - y log 3( x − 2) + 1 y 0 (the x axis) They intersect when log 3( x − 2) + 1 0 Using the rules of logs we take antilog of each side. log 3( x − 2) + 1 log3( x − 2) 0 −1 ( x − 2) −1 3 x 2+ 1 7 3 3 1 8. Given: - a 2⋅ ( 4 − t) 2 and the point starts from REST. To get the velocity equation we integrate the acceleration equation above. v v ⌠ ⎮ a dt ⌡ −4 3 ⌠ 1 ⎮ 2 ⎮ 2⋅ ( 4 − t) dt ⌡ ⋅ ( 4 − t) 3 2 3 2 2 2⋅ ⋅ ( 4 − t) ⋅ ( −1) + C 3 +C when t = 0 then v = 0 (starting from rest) then we have 0 −4 3 3 ⋅ ( 4 − 0) 2 +C C Hence equation is v 32 3 −4 3 ⋅ ( 4 − t) 3 2 Page 7 of 9 + 32 3 Scottish Higher Still Course www.mathsrevision.com Higher Still Level Exam 2002 Paper 2 Created by Graduate Bsc (Hons) MathsSci (Open) GIMA 9. Given:- 2 ( 1 − 2k) ⋅ x − 5⋅ kx − 2⋅ k 0 To have real roots for all integer values of k we need 2 b − 4ac ≥ 0 Hence we have 2 ( −5k) − 4⋅ ( 1 − 2k) ( −2k) ≥ 0 2 2 25k + 8k − 16k ≥ 0 2 9k + 8k ≥ 0 Since 9k2 is always positive for all values of k and 9k2 > 8k for all integers values of k, then the equation has real roots for all integer values of k. Page 8 of 9 Scottish Higher Still Course www.mathsrevision.com Higher Still Level Exam 2002 Paper 2 Created by Graduate Bsc (Hons) MathsSci (Open) GIMA 10. y Given the sketch:- (0,6) cos ( θ ) (a)(i) 8 a 10 L 10 Rearranging we get L 5 4 L ⋅a O (b)(ii) sin ( θ ) b 6 ( 8 − a) 10 Rearranging we get b Area rectangle L⋅ b 3 5 (a,0) (8,0) x ⋅ ( 8 − a) 3 ⋅ a⋅ ⎢⎡ ⋅ ( 8 − a)⎥⎤ 4 ⎣5 ⎦ 5 θ θ 3 4 ⋅ a⋅ ( 8 − a) Maximum / Minimum values are when A'(a) = 0. 3 A 4 ⋅ a ⋅ ( 8 − a) d A da 6− 6⋅ a 4 6a − 3 4 ⋅a 2 0 rearranging we get a 24 6 4 This is a maximum value because the constant term for a2 in the equation A (a) is negative (-3/4). Page 9 of 9