FOR EDEXCEL GCE Examinations Advanced Subsidiary Core Mathematics C2 Paper H MARKING GUIDE This guide is intended to be as helpful as possible to teachers by providing concise solutions and indicating how marks could be awarded. There are obviously alternative methods that would also gain full marks. Method marks (M) are awarded for knowing and using a method. Accuracy marks (A) can only be awarded when a correct method has been used. (B) marks are independent of method marks. Written by Shaun Armstrong Solomon Press These sheets may be copied for use solely by the purchaser’s institute. C2 Paper H – Marking Guide 1. 2. (a) x2 + (y − 3)2 − 9 − 7 = 0 ∴ centre (0, 3) M1 A1 (b) x2 + (y − 3)2 = 16 ∴ radius = 4 M1 A1 (a) 9 2 P = 2r + (r × 2.5) = r = 36 M1 OA = r = 8 cm 3. × 8 × 2.5) − ( (b) =( (a) 7 − 2x − 3x2 = (b) A1 2 1 2 2 x 2 1 2 , 2 × 8 × sin 2.5) = 60.8 cm (3sf) M2 A1 7x − 2x2 − 3x3 = 2 M1 3x3 + 2x2 − 7x + 2 = 0 A1 x = −2 is a solution ∴ (x + 2) is a factor 3x2 − 4x x + 2 3x3 + 2x2 3x3 + 6x2 2 − 4x 2 − 4x (a) (b) + 1 − 7x + 2 − 7x − 8x x + 2 x + 2 M1 A1 (a) (8) M1 A1 2 3 = 1 + 4( 2 ) + 6( 2 ) + 4( 2 ) + ( 2 ) (ii) 5. M1 A2 = 1 + 4x + 6x2 + 4x3 + x4 (i) (5) B1 ∴ (x + 2)(3x2 − 4x + 1) = 0 (x + 2)(3x − 1)(x − 1) = 0 x = −2 (at P), 13 , 1 ∴ ( 13 , 6), (1, 2) 4. (4) 4 M1 = 1 + 4 2 + 6(2) + 4( 2 2 ) + 4 M1 = 17 + 12 2 A1 4 (1 − 2 ) = 17 − 12 2 B1 (1 − 2 )8 = [(1 − M1 2 )4]2 = (17 − 12 2 )2 = 289 − 408 2 + 288 M1 = 577 − 408 2 A1 reflection in the y-axis y B1 y = ( 13 )x (b) (9) y = 2(3x) B3 (0, 2) (0, 1) (c) ( 13 )x = 2(3x) O x 2 1 = 2 × (3 ) 32x = x= 1 2 2 lg 3 3x = M1 , 2x = lg 12 lg 12 M1 lg 3 = −0.32 1 2 × y = 2(3x) = 2 × 1 2 C2H MARKS page 2 1 2 = x A1 2 2 = 2 = 1 2 2 M1 2 A1 Solomon Press (9) 6. (a) (b) 7. (a) dy = 3x2 + 2ax − 15 dx SP when x = −1 ∴ 3 − 2a − 15 = 0 a = −6 y = x3 − 6x2 − 15x + b (−1, 12) on curve ∴ 12 = −1 − 6 + 15 + b b=4 M1 A1 M1 A1 3x2 − 12x − 15 = 0 3(x − 5)(x + 1) = 0 x = −1 [at (−1, 12)] or 5 ∴ (5, −96) 1 − 8x3 M1 M1 A1 1 − 8x3 = 0 =0 ⇒ x2 x3 = x= (b) M1 A1 M1 1 8 1 2 M1 A1 f(x) = x−2 − 8x −2 ∫ f(x) dx = ∫ (x − 8x) dx = −x−1 − 4x2 + c (c) 8. (a) M1 A2 2 2 −1 = −[−x − 4x ] 1 M1 = −{( − 12 − 16) − (−2 − 1)} = 13 12 M1 A1 sin2 θ = (2 − M1 2 2 )2 = 4 − 4 2 + 2 = 6 − 4 2 2 cos θ = 1 − (6 − 4 2 ) = −5 + 4 2 (b) 2x − π 6 2x = π 2 , , 11π 12 x= 9. (a) (9) π 4 π 3 = , 2π − π 3 = π 3 , M1 A1 5π 3 B1 M1 11π 6 M1 A1 M1 A2 ar = −48, ar4 = 6 3 r = 6 −48 = 3 a= −48 − 12 = (c) Sn = M1 M1 A1 = 96 96 1 − (− 12 ) (b) A1 = 64 96[1 − (− 12 )n ] 1 − (− 12 ) M1 A1 = 64[1 − ( − 12 )n] M1 A1 S∞ − Sn = 64 − 64[1 − ( − 12 )n] = (10) B1 − 18 − 18 = − 12 r= (9) 64( − 12 )n 6 M1 −n n n = 2 × (−1) × 2 = (−1) × 2 difference is magnitude, ∴ = 2 6−n 6−n Solomon Press M1 A1 (12) Total (75) C2H MARKS page 3 Performance Record – C2 Paper H Question no. 1 2 Topic(s) circle sector of a circle Marks 4 5 3 4 factor binomial exponential graphs, theorem, logs alg. div. 8 9 Student C2H MARKS page 4 5 Solomon Press 9 6 7 8 9 SP area by integr. trig. eqn GP 9 9 10 12 Total 75