FOR OCR GCE Examinations Advanced / Advanced Subsidiary Core Mathematics C2 Paper L 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 using a valid 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 L – Marking Guide 1. (i) y x 2 y = tan B2 y = sin 2x O (ii) 2. x 4 solutions the graphs intersect at 4 points area of segment = ( 12 × r2 × 1 2 rπ 6 = shaded area = 3. 4. B2 1 6 π 3 ) − ( 12 × r2 × sin 1 2 r 4 − 2 r π − 2( 16 r π − 1 2 rπ 3 = − = 1 2 r 2 3 − + 1 2 rπ 6 π 3 ) 3 2 1 2 rπ 6 B1 B1 2 r 1 2 r 2 3) M1 3 1 2 r (3 6 3 − π) A1 (i) u 2 = k2 − 1 u3 = (k2 − 1)2 − 1 = k4 − 2k2 B1 M1 A1 (ii) k4 − 2k2 + k2 − 1 = 11 k4 − k2 − 12 = 0 (k2 + 3)(k2 − 4) = 0 k2 = −3 (no solutions) or 4 k=±2 M1 M1 A1 A1 (i) x 0 0.5 1 1.5 2 1 1 0.8 0.5 0.3077 0.2 x2 + 1 area ≈ 1 2 × 0.5 × [1 + 0.2 + 2(0.8 + 0.5 + 0.3077)] = 1.10 (3sf) (ii) 5. B1 M2 A1 1 4 = (i) (ii) B1 M1 M1 A1 loga 27 − loga 8 = 3 =3 loga 27 8 M1 , a= 3 27 8 = 3 2 3lg 2 + lg 6 lg 6 − lg 2 C2L MARKS page 2 (7) M1 A1 (x + 3) lg 2 = (x − 1) lg 6 x(lg 6 − lg 2) = 3 lg 2 + lg 6 x= (7) M1 A1 area = 8 × 1.10385 = 70.6464 volume = 2 × 70.6464 = 141 cm3 (3sf) 27 8 (6) A1 2 a3 = (6) M1 M1 = 3.52 M1 A1 Solomon Press (7) 6. (i) = [2x + x−1] 42 = (8 + (ii) y= y= ∫ 1 4 M1 A1 ) − (4 + 1 2 3 34 )= M1 A1 (2x3 + 1) dx x4 + x + c 1 2 M1 A1 x = 0, y = 3 ∴ c = 3 y = 12 x4 + x + 3 when x = 2, y = 8 + 2 + 3 = 13 7. (i) 1 − 8x3 x2 =0 ⇒ M1 A1 1 − 8x3 = 0 M1 x3 = M1 x= (ii) B1 1 8 1 2 A1 −2 f(x) = x − 8x −2 ∫ f(x) dx = ∫ (x − 8x) dx = −x−1 − 4x2 + c (iii) 8. (i) (iii) M1 A2 = −[−x−1 − 4x2] 21 M1 = −{( − 12 − 16) − (−2 − 1)} = 13 12 M1 A1 2 S6 = 6 2 [3000 + (5 × −x)] = 8100 3000 − 5x = 2700, (ii) M1 A1 = 1500 − (7 × 60) = 1500 − 420 = £1080 Sn = n 2 9. (i) (ii) M1 A1 [3000 − 60(n − 1)] M1 [ k = 30 ] M1 A1 the value of sales in a month would become negative which is not possible B1 f(2) = 16 − 20 + 2 + 2 = 0 ∴ (x − 2) is a factor M1 A1 2x2 − x 3 2 x − 2 2x − 5x 3 2x − 4x2 2 − x 2 − x (10) 1 x + 2 − + + x + 2x − x + 2 − x + 2 M1 A1 f(x) = (x − 2)(2x2 − x − 1) f(x) = (x − 2)(2x + 1)(x − 1) M1 A1 (iii) x = − 12 , 1, 2 B1 (iv) sin θ = 2 (no solutions), − 12 or 1 θ =π+ θ = π 2 , π 6 7π 6 , 2π − , π 6 or (9) M1 A1 x = 60 = n[1500 − 30(n − 1)] = 30n[50 − (n − 1)] = 30n(51 − n) (iv) (9) π 2 M1 B1 11π 6 Solomon Press A2 (11) Total (72) C2L MARKS page 3 Performance Record – C2 Paper L Question no. 1 2 Topic(s) trig. graphs sector of a circle Marks 6 6 3 4 sequence trapezium rule 7 5 6 7 8 9 logs integr. area by integr. AP factor theorem, alg. div., trig. eqn 7 9 9 10 11 7 Student C2L MARKS page 4 Solomon Press Total 72
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