FOR EDEXCEL GCE Examinations Advanced Subsidiary Core Mathematics C3 Paper A 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. C3 Paper A – Marking Guide 1. 2. dx dy = 2 sec y × sec y tan y + sec2 y = sec2 y(2 tan y + 1) = 2 tan 2y + 1 dy dx =1÷ cos y dx dy cos 2 y 2 tan y + 1 = (a) = f( 12 ) = − 52 (b) gf(x) = ∴ M1 A1 = 2 3x − 1 M1 A1 =6 2 = 6(3x − 1) x = 49 3. e2y − x + 2 = 0 sub. ⇒ e2y = x − 2 2y = ln (x − 2) ln (x + 3) − ln (x − 2) − 1 = 0 x+3 x−2 x+3 = x−2 d dx M1 e A1 x + 3 = e(x − 2) 3 + 2e = x(e − 1) M1 M1 2e + 3 e −1 (tan x) = = = (b) dy dx x= , y= ∴ y− π 2 (a) 1 2 ln ( 2e + 3 e −1 − 2) = 0.53 (2dp) d sin x dx cos x cos x × cos x − sin x × (− sin x) cos 2 x cos 2 x + sin 2 x cos 2 x π 2 = 1 cos 2 x = sec2 x , grad = 2 + π = (2 + π)(x − at P, x = 0 ∴ y = π2 − 5. = 4.91 (2dp), y = = 2 × tan x + 2x × sec2 x = 2 tan x + 2x sec2 x π 4 π 4 π 4 A2 (8) M1 A1 M1 A1 M1 A1 B1 ) M1 (2 + π) = − 14 π2 M1 A1 (10) 3 cos x + sin x = R cos x cos α + R sin x sin α R cos α = 3, R sin α = 1 ∴ R = 32 + 12 = 10 tan α = 13 , α = 18.4 (3sf) ∴ 3 cos x° + sin x° = (b) (6) M1 A1 =1 x= (a) M1 A1 ⇒ ln 4. (4) M1 A1 2 (3x − 4) + 3 2 3x − 1 M1 A1 M1 A1 M1 A1 10 cos (x − 18.4)° 2 6 cos x + 2 sin x cos x = 0 2 cos x(3 cos x + sin x) = 0 cos x = 0 or 3 cos x + sin x = 10 cos (x − 18.4) = 0 x = 90, 270 or x − 18.4 = 90, 270 x = 90, 108.4 (1dp), 270, 288.4 (1dp) Solomon Press C3A MARKS page 2 M1 M1 A1 B1 M1 A1 (10) 6. (a) (i) y (ii) y y=2 (0, q) y=4 (p, 0) O M1 A1 M2 A2 x (p − 1, 0) x=1 O x=0 (b) y = 0 ⇒ 2x − 1 = 0 ⇒ x = 1 2 ∴p= x 1 2 M1 A1 x=0 ⇒ y=1 ∴q=1 (c) y= 2x − 1 , x −1 y(x − 1) = 2x − 1 x(y − 2) = y − 1, (a) (b) M1 y −1 y−2 x= M1 x −1 x−2 ∴ f −1(x) = 7. B1 A1 (i) LHS = sin x cos 30 + cos x sin 30 + sin x cos 30 − cos x sin 30 = 2 sin x cos 30 = 3 sin x [a = 3 ] (ii) let x = 45, sin 75 + sin 15 = 3 sin 45 = 3× 1 2 = 1 2 6 2(cosec2 y − 1) + 5 cosec y + cosec2 y = 0 3 cosec2 y + 5 cosec y − 2 = 0, (3 cosec y − 1)(cosec y + 2) = 0 cosec y = −2 or 13 (no solutions) (12) M1 A1 A1 M2 A1 M1 M1 A1 sin y = − 12 y = 180 + 30, 360 − 30 y = 210, 330 8. (a) 2 x +x−6 x2 + 0 x + 1 x4 + x3 − 5 x2 + 0 x x4 + x3 − 6 x2 x2 + 0 x x2 + x − x ∴ f(x) = x2 + 1 + = x2 + 1 − (b) B1 M1 A1 M1 A1 − 9 − 6 − 3 A1 = x2 + 1 − 1 x−2 [A = 1, B = −1, C = −2] M1 A1 y y = x2 + 1 y= 1 x−2 O f(x) = 0 ⇒ x2 + 1 = (c) − 9 −x − 3 x2 + x − 6 x+3 ( x − 2)( x + 3) (12) B2 x 1 x−2 , graphs intersect once ∴ exactly one real root B1 e.g. x0 = 3, x1 = 2.1, x2 = 2.1848, x3 = 2.1732, x4 = 2.1747 ∴ root = 2.17 (3sf) f(2.165) = −0.37, f(2.175) = 0.016 sign change, f(x) continuous ∴ root M1 A1 A1 M1 A1 (13) Total (75) Solomon Press C3A MARKS page 3 Performance Record – C3 Paper A Question no. Topic(s) 1 2 3 4 5 6 7 8 Total differentiation functions exponentials differentiation trigonometry functions trigonometry rational and expressions, logarithms numerical methods Marks 4 6 8 10 Student Solomon Press C3A MARKS page 4 10 12 12 13 75 FOR EDEXCEL GCE Examinations Advanced Subsidiary Core Mathematics C3 Paper B 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. C3 Paper B – Marking Guide 1. ( x + 3)( x + 4) (2 x + 1)( x + 4) x+3 2x + 1 (a) = (b) ln (x2 + 7x + 12) − ln (2x2 + 9x + 4) = 1, x+3 2x + 1 ln = x+3 2x + 1 = 1, x + 3 = e(2x + 1), (a) x 2 + 7 x + 12 2x2 + 9x + 4 1 A1 3 − e = x(2e − 1) M1 ×3= M1 A1 A1 3 4 5 ∴ y− 2 5 = (x − 3) M1 4 5 y − 40 = 3x − 9 3x − 4 5 y + 31 = 0 (b) A1 y− 2 5 =−4 normal: 5 3 (x − 3) at Q, x = 0 ∴ y − 2 5 = 4 5 , 3. (a) y= 6 5 adding, P + Q = 2A ⇒ A = subtracting, P − Q = 2B ⇒ B = P+Q 2 2 sin 3x cos 2x = 0 sin 3x = 0 or cos 2x = 0 3x = 0, π, 2π or 2x = π2 , π 4 x = 0, 4. M1 sin (A + B) ≡ sin A cos B + cos A sin B sin (A − B) ≡ sin A cos B − cos A sin B adding, sin (A + B) + sin (A − B) ≡ 2 sin A cos B let P = A + B, Q = A − B ∴ sin P + sin Q ≡ 2 sin (b) (a) (4, 0) (b) dy dx 2π 3 , cos P+Q 2 P−Q 2 P−Q 2 3 2 x × ln − 18 ∴ y−0= x 4 M1 A1 M1 3π 2 A2 5 2 + x × 1 x = 1 2 3 2 x (5 ln x 4 + 2) area = ln 1 2 × 3 2 x (5 ln x 4 x 4 1 2 x = 4e M1 A1 M1 1 2 A1 ×4=1 A1 + 2) = 0 = − 52 M1 − 52 M1 A1 Solomon Press C3B MARKS page 2 (9) A1 (x − 4) at Q, x = 0, y = 1 2 M1 A1 A1 grad = 8, grad of normal = − 18 (c) (9) M1 3π 4 , M1 A1 B1 5 2 = π 3 , (7) B1 1 − 3 (3x + 11) 2 2 3 4 5 grad = M1 =e 20 = 2 5 − 1 (3x + 11) 2 2 = =1 A1 x = 3, y = dy dx ln 3−e 2e − 1 x= 2. M1 A2 (10) 5. (a) = 2[x2 + 2x] + 2 = 2[(x + 1)2 − 1] + 2 = 2(x + 1)2 M1 A1 (b) translation by 1 unit in negative x direction stretch by scale factor of 2 in y direction (either first) B3 (c) y 2 y = 2(x + 1)2, x+1=± y 2 x = −1 ± y 2 (d) = (x + 1)2 M1 M1 (domain ⇒ +), ∴ f −1(x) = −1 + x 2 , x∈ , x≥0 A2 y y = f(x) B3 y = f −1(x) is reflection of y = f(x) in line y = x −1 y = f (x) O 6. x (13) (a) f(x) > −2 B1 (b) x = 0, y = e − 2 ∴ P (0, e − 2) y = 0, 0 = e3x + 1 − 2 3x + 1 = ln 2 x = 13 (ln 2 − 1) ∴ Q ( 13 (ln 2 − 1), 0) B1 M1 M1 A1 (c) f ′(x) = 3e3x + 1 at P, grad = 3e ∴ y − (e − 2) = 3e(x − 0) y = 3ex + e − 2 M1 A1 M1 A1 (d) at Q, grad = 6 tangent at Q: y − 0 = 6(x − 1 3 (ln 2 − 1)) y = 6x − 2 ln 2 + 2 intersect: 3ex + e − 2 = 6x − 2 ln 2 + 2 x(3e − 6) = 4 − e − 2 ln 2 4 − e − 2 ln 2 3e − 6 x= 7. B1 (a) arccos θ = (b) π 3 , θ = cos = −0.0485 (3sf) π 3 = 1 2 A1 (13) y −2 (d) M1 M1 A1 x+2 B2 y = arccos (x − 1) B3 y= (c) B1 M1 O 2 x let f(x) = arccos (x − 1) − x + 2 f(0) = 1.7, f(1) = −0.16 sign change, f(x) continuous ∴ root M1 A1 A1 x1 = 0.83944, x2 = 0.88598, x3 = 0.87233, x4 = 0.87632, x5 = 0.87515, x6 = 0.87549 ∴ α = 0.875 (3dp) M1 A2 A1 (14) Total (75) Solomon Press C3B MARKS page 3 Performance Record – C3 Paper B Question no. Topic(s) 1 2 3 4 rational differentiation trigonometry differentiation expressions, exponentials and logarithms Marks 7 9 9 10 Student Solomon Press C3B MARKS page 4 5 functions 13 6 7 Total exponentials trigonometry, and numerical logarithms, methods differentiation 13 14 75 FOR EDEXCEL GCE Examinations Advanced Subsidiary Core Mathematics C3 Paper C 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. C3 Paper C – Marking Guide 1. (a) (b) 2. (a) = x+4 (2 x + 1)( x + 1) = ( x + 4) − 2( x + 1) (2 x + 1)( x + 1) M1 = 2− x (2 x + 1)( x + 1) A1 2− x (2 x + 1)( x + 1) = 2 2x + 1 − M1 1 2 2(2 − x) = 2x2 + 3x + 1 2x2 + 5x − 3 = 0 (2x − 1)(x + 3) = 0 x = −3, 12 M1 A1 if θ = M1 π 2 M1 , sin θ = 1, cosec θ = 1 ∴ cosec θ − sin θ = 1 − 1 = 0 ∴ statement is false (b) 1 − sin θ = 2 sin θ sin2 θ + 2 sin θ − 1 = 0 M1 2 (no solutions) or −1 + 2 5. 2 M1 A1 θ = 0.4271, π − 0.4271 θ = 0.43, 2.71 (2dp) M1 A1 (a) 2x − 3 = e x = 12 (e + 3) M1 M1 A1 (b) 3e2y − 16ey + 5 = 0 (3ey − 1)(ey − 5) = 0 ey = 13 , 5 M1 M1 A1 y = ln 4. A1 2 sin θ = −2 ± 4 + 4 = −1 − 3. 1 3 , ln 5 ×3= M1 A1 (a) = 1 3x − 2 (b) = 2 × (1 − x ) − (2 x + 1) × (−1) 3 3x − 2 (c) = (a) (i) (1 − x)2 3 2 3 1 (6) (7) (8) M1 A1 = x 2 × e2x + x 2 × 2e2x = 3 M1 A2 (1 − x )2 1 2 1 x 2 e2x(3 + 4x) y M1 A2 (ii) (8) y 3 2 ( − , 6) O x B3 (−2, −4) (2, −4) O x M2 A2 (1, −12) (b) a = 4, b = 2 B2 Solomon Press C3C MARKS page 2 (9) 6. (a) 4 − ln 3x = 0, (b) ln 3x = 4, x= 1 3 e4 y ( 13 e4, 0) O (c) 7. (a) B2 x y = 4 − ln 3x ln 3x = 4 − y x = 13 e4 − y ∴ f −1(x) = (d) M1 A1 M1 M1 e4 − x 1 3 A1 2−x fg(x) = 4 − ln 3e = 4 − (ln 3 + ln e2 − x) = 4 − ln 3 − (2 − x) = x + 2 − ln 3 [a = 2, b = 3] M1 M1 A1 (10) 4 sin x + 3 cos x = R sin x cos α + R cos x sin α R cos α = 4, R sin α = 3 ∴ R = 42 + 32 = 5 tan α = 34 , α = 0.644 (3sf) M1 A1 M1 A1 ∴ 4 sin x + 3 cos x = 5 sin (x + 0.644) (b) (c) 8. (a) minimum = −5 occurs when x + 0.6435 = 3π 2 5 sin (2θ + 0.6435) = 2 sin (2θ + 0.6435) = 0.4 2θ + 0.6435 = π − 0.4115, 2π + 0.4115 2θ = 2.087, 6.051 θ = 1.04, 3.03 (2dp) dy dx = 1 2 x − 12 − 4e1 − 4x ∴ y− SP: 3 2 = 1 2 − 12 x 1 8 x (c) (d) (e) 1 3 (x − 1 4 M1 B1 M1 M1 A2 ) 1 3 A1 [ 4x − 12y + 17 = 0 ] − 4e1 − 4x = 0, 1 2 x M1 A1 = 4e1 − 4x = e1 − 4x M1 8 x = e4x − 1 4x − 1 = ln 8 x x = 14 (1 + ln 8 x ) M1 A1 x1 = 0.7699, x2 = 0.7372, x3 = 0.7317, x4 = 0.7308 = 0.731 (3dp) let f(x) = 1 2 x − 12 (13) M1 grad = −3, grad of normal = (b) , x = 4.07 (3sf) B1 M1 A1 M1 A2 − 4e1 − 4x f(0.7305) = −0.00025, f(0.7315) = 0.0017 sign change, f(x) continuous ∴ root M1 A1 x1 = 6.304, x2 = 1.683 × 1019 diverges rapidly away from root B2 (14) Total (75) Solomon Press C3C MARKS page 3 Performance Record – C3 Paper C Question no. Topic(s) 1 2 3 4 5 6 7 8 Total rational trigonometry exponentials differentiation functions functions trigonometry differentiation, expressions and numerical logarithms methods Marks 6 7 8 8 Student Solomon Press C3C MARKS page 4 9 10 13 14 75 FOR EDEXCEL GCE Examinations Advanced Subsidiary Core Mathematics C3 Paper D 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. C3 Paper D – Marking Guide 1. (a) (b) = f(2) = 2 + ln 4 y = 2 + ln (3x − 2), x = 13 (2 + ey − 2) f −1(x) = 2. M1 A1 1 3 3x − 2 = e y−2 M1 (2 + ex − 2) M1 A1 3(cosec2 x − 1) − 4 cosec x + cosec2 x = 0 4 cosec2 x − 4 cosec x − 3 = 0 (2 cosec x + 1)(2 cosec x − 3) = 0 cosec x = − 12 or 32 sin x = −2 (no solutions) or M1 M1 A1 2 3 M1 x = 0.73, π − 0.7297 x = 0.73, 2.41 (2dp) 3. (a) (i) = y ln 2 y ln 2 = = ln x − ln e = 2 ln x − 1 = 2y − 1 M1 A1 = 4 − (2y − 1) M1 y = (5 − 2y)ln 2 y(2 ln 2 + 1) = 5 ln 2 y= M1 5ln 2 2ln 2 + 1 A1 y x = e = 4.27 (2dp) 4. (a) LHS ≡ ≡ (b) 5. (a) (b) A1 2sin( x + y ) cos( x − y ) 2 cos( x + y ) cos( x − y ) M1 A1 sin( x + y ) cos( x + y ) M1 A1 ≡ tan (x + y) ≡ RHS let x = 30°, y = 22.5° ∴ tan (30 + 22.5) = tan 52.5 = 3 + 1 2 2 1+ 1 2 2 = = 3+ 2 1+ 2 × = f(x) = 3 − 3+ 2 1+ 2 + = M1 M1 6 − 3 − 2 +2 x + 11 (2 x + 1)( x − 3) A1 M1 A1 = 4 x 2 − 13x + 3 (2 x + 1)( x − 3) M1 A1 (4 x − 1)( x − 3) (2 x + 1)( x − 3) f ′(x) = 4 × (2 x + 1) − (42x − 1) × 2 = (2 x + 1) x = −2 ⇒ y = 3, grad = 2 3 = 4x −1 2x + 1 6 (2 x + 1)2 2 3 M1 A1 A1 (x + 2) M1 3y − 9 = 2x + 4 2x − 3y + 13 = 0 A1 Solomon Press C3D MARKS page 2 (9) B1 3(2 x 2 − 5 x − 3) − ( x − 1)(2 x + 1) + ( x + 11) (2 x + 1)( x − 3) = (8) B1 A1 1− 2 1− 2 3− 6 + 2−2 1− 2 x −1 x−3 sin 60 + sin 45 cos 60 + cos 45 = ∴ y−3= (6) M1 A1 2 (ii) (b) A2 ln x ln 2 (5) (10) 6. (a) (b) (c) dy = 3e3x × cos 2x + e3x × (−2 sin 2x) = e3x(3 cos 2x − 2 sin 2x) dx d2 y dx 2 = 3e3x × (3 cos 2x − 2 sin 2x) + e3x(−6 sin 2x − 4 cos 2x) M1 A1 = e3x(5 cos 2x − 12 sin 2x) A1 3x e (3 cos 2x − 2 sin 2x) = 0 3 cos 2x = 2 sin 2x tan 2x = 32 SP: 2x = 0.98279, 7. d y when x = 0.491, (a) dx M1 M1 x = 0.491 (3sf) 2 (d) M1 A1 2 = −31.5, 2 d y dx 2 M1 A1 < 0 ∴ maximum M1 A1 (11) y (0, 4a2) y = 2x − a y = 4 a 2 − x2 (0, a) O ( 12 a, 0) (2a, 0) (−2a, 0) (b) B3 B3 x 4 − x2 = 2 x − 1 x2 + 2x − 5 = 0, x> 1 2 ∴ x = −1 + M1 x= −2 ± 4 + 20 2 = −2 ± 2 6 2 M1 6 A1 2 4 − x = −(2x − 1) x2 − 2 x − 3 = 0 (x + 1)(x − 3) = 0 x < 12 ∴ x = −1, 8. (a) x = −1, −1 + M1 A1 6 dy 3 6 =2− ×2=2− 2x + 5 2x + 5 dx grad = −4, grad of normal = 14 ∴ y+4= (b) M1 1 4 7 4 x− x+ 7 2 7 2 1 4 (x + 2) [y= M1 A1 1 4 x− 7 2 ] M1 A1 = 2x − 3 ln (2x + 5) − 3 ln (2x + 5) = 0, M1 let f(x) = 7 4 x+ 7 2 − 3 ln (2x + 5) f(1) = −0.59, f(2) = 0.41 sign change, f(x) continuous ∴ root (c) (d) 7 4 x+ 7 2 (12) M1 A1 − 3 ln (2x + 5) = 0 7x + 14 − 12 ln (2x + 5) = 0 7x = 12 ln (2x + 5) − 14 x = 127 ln (2x + 5) − 2 M1 A1 x1 = 1.5648, x2 = 1.5923, x3 = 1.6039, x4 = 1.6087, x5 = 1.6107 q = 1.61 (3sf) f(1.605) = −0.0073, f(1.615) = 0.0029 sign change, f(x) continuous ∴ root ∴ q = 1.61 (3sf) M1 A1 A1 M1 A1 (14) Total (75) Solomon Press C3D MARKS page 3 Performance Record – C3 Paper D Question no. Topic(s) Marks 1 2 3 4 5 6 7 8 Total functions trigonometry exponentials trigonometry rational differentiation functions differentiation, and expressions, numerical logarithms differentiation methods 5 6 8 9 10 Student Solomon Press C3D MARKS page 4 11 12 14 75 FOR EDEXCEL GCE Examinations Advanced Subsidiary Core Mathematics C3 Paper E 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. C3 Paper E – Marking Guide 1. 2. = x 2 (2 x + 1) ( x + 2)( x − 2) = x2 ( x + 2)( x − 3) (a) x−2 (2 x + 1)( x − 3) × M1 A2 M1 A1 sin x cos x LHS ≡ 2 sin x cos x − M1 2 ≡ 2sin x cos x − sin x M1 A1 cos x 2 sin x ≡ sin x(2 cos x − 1) ≡ × cos 2x ≡ tan x cos 2x ≡ RHS cos x (b) 3. M1 A1 B1 M1 A1 (a) f(1) = 2.30, f(1.5) = −18.5 sign change, f(x) continuous ∴ root M1 A1 (b) x2 + 5x − 2 sec x = 0 ⇒ 2 cos x 2 x2 + 5x = cos x = (a) (b) (a) A1 M1 1 − 1 (1 − cos x) 2 2 × sin x = = (ii) = 3x2 × ln x + x3 × dx = dy 1 x 1× (3 − 2 y ) − ( y + 1) × (−2) (3 − 2 y )2 1 5 sin x 2 1 − cos x (11) M1 A2 = x2(3 ln x + 1) M1 A2 5 = M1 A1 M1 A2 (3 − 2 y )2 (3 − 2y)2 M1 A1 (11) 3 sin θ + cos θ = R sin θ cos α + R cos θ sin α tan α = (c) 2 x2 + 5x f ′(x) = 2x + 5 − 2 sec x tan x SP: 2x + 5 − 2 sec x tan x = 0 f ′(1.05345) = 0.00046, f ′(1.05355) = −0.0022 sign change, f ′(x) continuous ∴ root ∴ x-coord of P = 1.0535 (5sf) R cos α = (b) ∴ g(x) = x2 + 5x M1 A2 dy dx =1÷ = dy dx 5. M1 x1 = 1.3119, x2 = 1.3269, x3 = 1.3302, x4 = 1.3310 = 1.331 (3dp) (i) (10) M1 x2 + 5x 2 x = arccos 4. M1 A1 cos x tan x cos 2x = 2 cos 2x cos 2x (tan x − 2) = 0 cos 2x = 0 or tan x = 2 2x = 90, 270 or x = 63.4 x = 45°, 63.4° (1dp), 135° (c) (5) 1 3 3 , R sin α = 1 , α= π 6 maximum = 2 occurs when θ + π 6 2 sin (θ + 3 = 0, θ + π 6 π 6 )+ = − π3 , −π + ∴ = π 3 π 2 ∴ R= 3 +1 = 2 3 sin θ + cos θ = 2 sin (θ + , θ = ) M1 A1 B1 M1 A1 π 3 sin (θ + π 6 )=− 3 2 = − π3 , − 2π 3 M1 B1 M1 θ = − 5π6 , − π2 A2 Solomon Press C3E MARKS page 2 M1 A1 π 6 (12) 6. (a) f(x) ≤ 3 B1 (b) y y = f(x) y = f −1(x) O (c) B3 x y = 3 − x2 x2 = 3 − y x = ± 3− y M1 f −1(x) = M1 A2 3− x , x ∈ , x ≤ 3 4 3 (d) = f( ) = (e) 3− x = 3−x= 11 9 M1 A1 8 3− x 64 M1 (3 − x )2 (3 − x)3 = 64 3−x=4 x = −1 7. (a) M1 A1 10k M1 ⇒ A= sub (2) ⇒ 7 = 13e10k × e−60k 7 e−50k = 13 A1 = 0.0124 (3sf) M1 A1 1 − 50 7 ln 13 10 × 0.01238 ∴ A = 13e (c) 13 (1) (2) (1) ∴ k= (b) 18 = 5 + Ae−10k 12 = 5 + Ae−60k ⇒ ⇒ t = 10, T = 18 t = 60, T = 12 (13) e−10 k = 13e = 14.7 (3sf) M1 A1 T = 5 + 14.71e−0.01238t dT = −0.01238 × 14.71 e−0.01238t = −0.1822e−0.01238t dt dT = −0.1822e−0.01238 × 20 = −0.142 when t = 20, dt ∴ temperature decreasing at rate of 0.142 °C per minute (3sf) −0.01238(t − 60) T = 5 + 14.71e = 5 + 14.71e0.7428 − 0.01238t = 5 + 14.71e0.7428 × e−0.01238t B = 30.9 (3sf) = 5 + 30.9e−0.01238t, M1 A1 M1 A1 M1 M1 A1 (13) Total (75) Solomon Press C3E MARKS page 3 Performance Record – C3 Paper E Question no. Topic(s) Marks 1 2 rational trigonometry expressions 5 10 3 4 6 numerical differentiation trigonometry functions methods, differentiation 11 11 Student Solomon Press C3E MARKS page 4 5 12 13 7 Total exponentials and logarithms, differentiation 13 75 FOR EDEXCEL GCE Examinations Advanced Subsidiary Core Mathematics C3 Paper F 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. C3 Paper F – Marking Guide 1. 2. 3. 3 sin θ = −8 cos θ M1 3 = −8 sin θ cos θ = −4 sin 2θ sin 2θ = − 34 M1 A1 2θ = 180 + 48.590, 360 − 48.590 = 228.590, 311.410 θ = 114.3, 155.7 (1dp) M1 A2 (a) g(x) = (x + a)2 − a2 + 2 ∴ g(x) ≥ 2 − a2 M1 A1 A1 (b) gf(3) = g(1 − 3a) = (1 − 3a)2 + 2a(1 − 3a) + 2 ∴ 1 − 6a + 9a2 + 2a − 6a2 + 2 = 7, 3a2 − 4a − 4 = 0 (3a + 2)(a − 2) = 0 a = − 23 , 2 M1 A1 M1 A1 (a) 3x + 1 = e2 x = 13 (e2 − 1) M1 M1 A1 (b) consider ln (3x2 + 5x + 3) ≥ 0 ⇒ 3x2 + 5x + 3 ≥ 1 3x2 + 5x + 2 ≥ 0 (3x + 2)(x + 1) ≥ 0 −1 − 23 M1 A1 ∴ if (e.g.) x = − 34 , ln (3x2 + 5x + 3) = ln ∴ if x = − 34 , ln (3x2 + 5x + 3) < 0 4. (a) dx =1× dy 1 − 2y + y × 1 − 2y − = y 1− 2 y 1 − 1 (1 − 2 y ) 2 2 (1 − 2 y ) − y 1− 2y = 15 16 = −0.0645... M1 ∴ statement is false A1 × (−2) = 1− 3y 1− 2 y M1 M1 A1 y = −1, x = − 3 , grad = ∴ y+1= 1 4 3 (x + 4y + 4 = 1 4 (a) 3 B1 3) M1 3x+3 3 x − 4y − 1 = 0 5. [ p = −4, q = −1 ] A1 (8) y ( π6 , 3) ( 7π , 1) 6 O x x= (b) (8) M1 A1 dy dx 1− 2 y = =1÷ 1− 3y dy dx (b) (7) M1 2 3 x ≤ −1 or x ≥ − (6) 2 + sec (x − x− π 6 =π− x= 5π 6 3π 2 , 2π 3 x= π 6 ) = 0, π 3 ,π+ sec (x − π 3 = 2π 3 , M2 A3 5π 3 π 6 ) = −2, cos (x − 4π 3 ) = − 12 M1 B1 M1 A2 Solomon Press C3F MARKS page 2 π 6 (10) 6. (a) y (−3, 6) (3, 6) (0, 4) O (b) x y B3 (c) y (−3, 3) (0, 8) (0, 2) O ( 32 , 0) x M2 A2 ( − 92 , 2) O 7. (a) (b) f(x) = 1 + y= x 4x 2x − 5 15 (2 x − 5)( x − 1) − = 2 x 2 − 7 x + 5 + 4 x( x − 1) − 15 (2 x − 5)( x − 1) = 6 x 2 − 11x − 10 (2 x − 5)( x − 1) 3x + 2 , x −1 M2 A2 = B1 M1 A1 (3x + 2)(2 x − 5) (2 x − 5)( x − 1) = 3x + 2 x −1 M1 A1 y(x − 1) = 3x + 2 M1 x(y − 3) = y + 2 M1 y+2 y−3 x= x+2 x−3 3( x − 1) + 5 = x −1 ∴ f −1(x) = f(x) = A1 3+ 5 x −1 M1 x < 1 ∴ f(x) < 3 ∴ domain of f −1(x) is x ∈ 8. , x<3 A1 −1 (c) f(x) = 2 ⇒ x = f (2) = −4 (a) dy = 2x − dx 1 (4 + ln 2 x) x = 1, y = −1, grad = ∴ y+1= 7 4 − 12 × M1 A1 1 x = 2x − 1 2 x 4 + ln x 7 4 A1 (x − 1) SP: 2x − 1 2 x 4 + ln x let f(x) = 2x − M1 A1 =0 1 2 x 4 + ln x M1 , f(0.3) = −0.40, f(0.4) = 0.088 M1 sign change, f(x) continuous ∴ root (c) 2x − 1 2 x 4 + ln x =0 ⇒ A1 2x = 1 2 x 4 + ln x x2 = 1 4 4 + ln x = 1 (4 + ln 4 x) x= (d) (12) M1 A1 4y + 4 = 7x − 7 7x − 4y = 11 (b) (11) 1 (4 + ln 4 − 12 = x) − 12 1 (4 + ln 2 M1 x) x1 = 0.38151, x2 = 0.37877, x3 = 0.37900, x4 = 0.37898 (5dp) − 14 A1 M1 A2 (13) Total (75) Solomon Press C3F MARKS page 3 Performance Record – C3 Paper F Question no. Topic(s) 1 2 3 4 5 6 7 8 Total trigonometry functions exponentials differentiation trigonometry functions rational differentiation, and expressions, numerical logarithms, functions methods proof Marks 6 7 8 8 10 Student Solomon Press C3F MARKS page 4 11 12 13 75 FOR EDEXCEL GCE Examinations Advanced Subsidiary Core Mathematics C3 Paper G 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. C3 Paper G – Marking Guide 1. (a) (b) 2. (a) (b) dy = 3(3x − 5)2 × 3 = 9(3x − 5)2 dx grad = 9 ∴ y − 1 = 9(x − 2) [ y = 9x − 17 ] A1 M1 A1 9(3x − 5)2 = 9 3x − 5 = ± 1 x = 2 (at P), 43 M1 A1 ∴ Q ( 43 , −1) A1 cos (A + B) ≡ cos A cos B − sin A sin B cos (A − B) ≡ cos A cos B + sin A sin B adding, 2 cos A cos B ≡ cos (A + B) + cos (A − B) M1 A1 2 cos (x + π 2 ) cos (x + cos (2x + 2π 3 ) + cos π 3 =1 M1 cos (2x + 2π 3 )=1− 1 2 = 1 2 A1 , 2π + π 3 2π 3 2x + 2x = π, x= 3. π 2 , 1 cos x π 3 = 2π − π 6 )=1 = 5π 3 , 7π 3 B1 M1 5π 6 A2 × (−sin x) = −tan x M1 A2 (a) = (b) = 2x × sin 3x + x2 × 3 cos 3x = 2x sin 3x + 3x2 cos 3x (c) = d −1 [ 6(2 x − 7) 2 ] dx (a) M1 A2 B1 ×2=− 22 + 32 = tan α = (c) (9) 6 M1 A2 3 (10) (2 x − 7) 2 2 sin x − 3 cos x = R sin x cos α − R cos x sin α R cos α = 2, R sin α = 3 ∴ R= (b) − 32 (7) M1 5π 3 = −3(2 x − 7) 4. M1 3 2 13 M1 A1 , α = 56.3 (3sf) M1 A1 ∴ 2 sin x° − 3 cos x° = 13 sin (x − 56.3)° cosec x° + 3 cot x° = 2 ⇒ 1 sin x ⇒ ⇒ 1 + 3 cos x = 2 sin x 2 sin x° − 3 cos x° = 1 + 3cos x sin x =2 B1 13 sin (x − 56.31) = 1 sin (x − 56.31) = 1 13 M1 x − 56.31 = 16.10, 180 − 16.10 = 16.10, 163.90 x = 72.4, 220.2 (1dp) Solomon Press C3G MARKS page 2 B1 M1 A2 (10) 5. (a) (b) let f(x) = 2x3 − x2 + 4x + 15 f( − 32 ) = − 27 − 94 − 6 + 15 = 0 ∴ (2x + 3) is a factor 4 x2 − 2x 2x + 3 2x3 − x2 2x3 + 3x2 2 − 4x 2 − 4x M1 A1 + 5 + 4x + 15 M1 A1 + 4x − 6x 10x + 15 10x + 15 ∴ f(x) = (2x + 3)(x2 − 2x + 5) ∴ (c) 2x2 + x − 3 3 2 x − x 2 + 4 x + 15 dy = dx SP: = (2 x + 3)( x − 1) (2 x + 3)( x 2 − 2 x + 5) 1× ( x 2 − 2 x + 5) − ( x − 1)(2 x − 2) 2 ( x − 2 x + 5) − x2 + 2 x + 3 ( x 2 − 2 x + 5)2 2 M1 A1 − x2 + 2 x + 3 M1 A2 ( x 2 − 2 x + 5)2 −(x + 1)(x − 3) = 0 ∴ (−1, − 14 ), (3, 14 ) M1 A2 (a) P = 30 + 50e0.002 × 30 = 83.1 ∴ population = 83 100 (3sf) M1 A1 (b) 30 + 50e0.002t > 84 e0.002t > 54 50 M1 A1 t> (c) (d) 7. x −1 x2 − 2 x + 5 =0 −x2 + 2x + 3 = 0, x = −1, 3 6. = = (a) 1 0.002 ln 54 , t > 38.5 ∴ 2018 50 30 + 50e0.002t = 26 + 50e0.003t, e0.003t − e0.002t = 0.08, e0.001t − 1 = 0.08e−0.002t 0.001t = ln (1 + 0.08e−0.002t) t = 1000 ln (1 + 0.08e−0.002t) M1 A1 50e0.003t − 50e0.002t = 4 e0.002t(e0.001t − 1) = 0.08 y (b, 0) A1 M1 A2 A1 (ii) O M1 A2 ( 13 a, 0) O (0, 2b) (c) (13) y x (0, a) (b) M1 M1 t1 = 69.887, t2 = 67.251, t3 = 67.595 ∴ 2047 (i) (12) x = 0 ⇒ y = −1 ∴ b = −1 y = 0 ⇒ 2 − x+9 = 0 x = 2 2 − 9 = −5 ∴ a = −5 y = 2 − x+9 , x+9 = 2 − y 2 x + 9 = (2 − y) x = (2 − y)2 − 9 ∴ f −1(x) = (2 − x)2 − 9 f(−9) = 2 ∴ domain of f −1(x) is x ∈ x M1 A2 B1 M1 A1 M1 , x≤2 M1 A1 M1 A1 (14) Total (75) Solomon Press C3G MARKS page 3 Performance Record – C3 Paper G Question no. Topic(s) 1 2 3 4 differentiation trigonometry differentiation trigonometry Marks 7 9 10 10 Student Solomon Press C3G MARKS page 4 5 6 7 Total rational exponentials functions expressions, and differentiation logarithms, numerical methods 12 13 14 75 FOR EDEXCEL GCE Examinations Advanced Subsidiary Core Mathematics C3 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. C3 Paper H – Marking Guide 1. (a) (b) = f(2) = −2 gf(x) = g(2 − x2) = 6 − 3x 2 ∴ 5(sec2 2θ 5 sec2 2θ (5 sec 2θ sec 2θ = = 3 − 2 x2 x2 = 2. M1 A1 9 4 1 2 2 3(2 − x ) 2(2 − x 2 ) − 1 6 − 3x = 2 M1 A1 3 − 2 x2 2(6 − 3x2) = 3 − 2x2 , x = ± 32 , M1 A1 − 1) − 13 sec 2θ = 1 − 13 sec 2θ − 6 = 0 + 2)(sec 2θ − 3) = 0 − 52 or 3 M1 M1 A1 cos 2θ = − 52 (no solutions) or 1 3 2θ = 70.529, 360 − 70.529, 360 + 70.529, 720 − 70.529 = 70.529, 289.471, 430.529, 649.471 θ = 35.3°, 144.7°, 215.3°, 324.7° (1dp) 3. (2 x − 3)( x + 3) (2 x − 3)( x − 2) (a) = (b) ln (2x2 + 3x − 9) − ln (2x2 − 7x + 6) = 2, ln x+3 x−2 = 2, 2 B1 M1 A2 x+3 x−2 = x+3 x−2 4. (a) 2 x2 + 3x − 9 ln 2x2 − 7 x + 6 =2 = e2 M1 A1 e2 − 1 ( 3π , 5) 2 B3 x ( π2 , −1) ( 3π 2 ⇒ −1 = a + b , −5) ⇒ −5 = a − b adding, B1 −6 = 2a ∴ a = −3, b = 2 −3 + 2 cosec x = 0, cosec x = x = 0.73, π − 0.7297, 5. 3 2 , sin x = M1 A1 2 3 x = 0.73, 2.41 (2dp) ⇒ 18 000 = 2000e3k, e3k = 9 k = 13 ln 9 = 0.732 (3sf) M1 A2 (a) t = 3, N = 18 000 (b) 4000 = 2000e0.7324t 1 t = 0.7324 ln 2 = 0.9464 hours M1 M1 A1 ∴ doubles in 57 minutes (nearest minute) A1 (c) (7) y O (c) M1 A1 2e 2 + 3 ( π2 , 1) (b) (7) M1 A2 x + 3 = e (x − 2) 3 + 2e2 = x(e2 − 1) x= (6) N = 2000e0.7324t, when t = 3, dN = 0.7324 × 2000e0.7324t = 1465e0.7324t dt M1 M1 A1 M1 A1 dN = 13 200 ∴ increasing at rate of 13 200 per hour (3sf) A1 dt Solomon Press C3H MARKS page 2 (9) (10) 6. (a) d d (sec x) = [(cos x)−1] dx dx = −(cos x)−2 × (−sin x) = sin x cos 2 x = 1 cos x × M1 A1 sin x cos x = sec x tan x (b) (c) 7. A1 dy = 2e2x × sec x + e2x × sec x tan x = e2x sec x (2 + tan x) dx x = 0, y = 1, grad = 2 ∴ y = 2x + 1 e2x sec x (2 + tan x) = 0 tan x = −2 x = −1.11 (2dp) SP: M1 A1 M1 A1 M1 M1 A1 (11) (a) f(x) = (x − 1)2 − 1 + 5 = (x − 1)2 + 4 M1 A1 (b) f(x) ≥ 4 B1 (c) y = (x − 1)2 + 4 (x − 1)2 = y − 4 x − 1 = ± y−4 M1 x=1± y−4 −1 x−4 f (x) = 1 + (d) (e) M1 A1 translation by 4 units in negative x direction translation by 1 unit in negative y direction (either first) dy −1 = 12 ( x − 4) 2 dx x = 8, y = 3, grad = (a) (b) (c) 1 4 A1 [ y = 35 − 4x ] dy = −e2x−2 + ex dx M1 A1 M1 A1 e2, grad = M1 x = 2, y = y= 3 2 3 4 3 2 2 e = 3 4 (12) M1 A1 SP: −e2x−2 + ex = 0 let f(x) = −e2x−2 + ex f(1.3) = −0.70, f(1.4) = 0.29 sign change, f(x) continuous ∴ root ∴ y− (d) B2 M1 ∴ grad of normal = −4 ∴ y − 3 = −4(x − 8) 8. M1 3 4 e2 2 e (x − 2) M1 M1 A1 2 ex ∴ x = 0 ⇒ y = 0 so passes through origin A1 x1 = −1.125589, x2 = −1.125803, x3 = −1.125804 (7sf) ∴ x-coordinate of B = −1.1258 (5sf) M1 A2 A1 (13) Total (75) Solomon Press C3H MARKS page 3 Performance Record – C3 Paper H Question no. Topic(s) Marks 1 2 functions trigonometry 6 7 3 4 5 7 8 Total rational functions, exponentials differentiation functions, differentiation, expressions, trigonometry and differentiation numerical exponentials logarithms, methods and differentiation logarithms 7 9 10 Student Solomon Press C3H MARKS page 4 6 11 12 13 75 FOR EDEXCEL GCE Examinations Advanced Subsidiary Core Mathematics C3 Paper I 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. C3 Paper I – Marking Guide 1. = = 2x 2 x + 3x − 5 2x (2 x + 5)( x − 1) = 2. x2 − x × 2 × M1 x3 x( x − 1) M1 A1 x3 2 x(2 x + 5) M1 A1 (a) A (0, 5), B (0, e2) ∴ AB = e2 − 5 B2 B1 (b) 3 + 2ex = ex + 2 = e2ex 3 = ex(e2 − 2) M1 ex = 3 e2 − 2 , x = ln ∴ y = e2ex = e2 × 3. (a) (b) 3 2 e −2 3 M1 A1 e2 − 2 = 3e2 M1 A1 2 e −2 2 2 f ′(x) = 2 x × (4 x + 1) − ( x2 + 3) × 4 = 4 x + 2 x −212 (4 x + 1) 4 x 2 + 2 x − 12 (4 x + 1)2 ≥0 M1 2(2x − 3)(x + 2) ≥ 0 x ≤ −2 or x ≥ (a) 3 2 dy 2 = 2x − 5 + x dx 5 3 −2 M1 A1 grad of normal = − 35 M1 ∴ y + 6 = − 35 (x − 3) M1 5y + 30 = −3x + 9 3x + 5y + 21 = 0 A1 2x − 5 + SP: 2 x =0 M1 M1 A1 (a) = g(5) = log2 16 = 4 M1 A1 (b) y = log2 (3x + 1) 3x + 1 = 2y x = 13 (2y − 1) M1 g−1(x) = M1 A1 (c) 1 3 (8) A1 2x2 − 5x + 2 = 0 (2x − 1)(x − 2) = 0 x = 12 , 2 5. M1 A1 3 2 M1 x = 3, y = −6, grad = (b) (8) M1 A2 (4 x + 1) for x ≠ − 14 , (4x + 1)2 > 0 ∴ 4x2 + 2x − 12 ≥ 0 4. (5) (2x − 1) fg−1(x) = f [ 13 (2x − 1)] = 2(2x − 1) − 1 = 2(2x) − 3 (8) M1 x ∴ 2(2 ) − 3 = 2 2x = 52 x= ln 52 ln 2 or A1 ln 5 − ln 2 ln 2 M1 A1 Solomon Press C3I MARKS page 2 (9) 6. (a) cos (A + B) ≡ cos A cos B − sin A sin B cos (A − B) ≡ cos A cos B + sin A sin B subtracting, cos (A + B) − cos (A − B) ≡ −2 sin A sin B let P = A + B, Q = A − B (b) 7. (a) P+Q 2 P−Q ⇒ B= 2 P+Q P−Q sin 2 2 adding, P + Q = 2A ⇒ A = subtracting, P − Q = 2B ∴ cos P − cos Q ≡ −2 sin M1 A1 M1 A1 (cos 5x − cos x) + sin 3x = 0 −2 sin 3x sin 2x + sin 3x = 0 sin 3x(1 − 2 sin 2x) = 0 sin 3x = 0 or sin 2x = 12 3x = 0, 180, 360 or 2x = 30, 150 x = 0, 15, 60, 75, 120 (i) y M1 M1 A1 B1 M1 A2 (ii) (11) y B3 O (0, 0) (0, 0) O (2a, 0) (b) = f(3a2) = 9a4 − 6a3 (2a, 0) x B3 M1 A1 2 gf(x) = 3a(x − 2ax) ∴ 3a(x2 − 2ax) = 9a3 x2 − 2ax − 3a2 = 0 (x + a)(x − 3a) = 0 x = −a, 3a M1 (a) f(0.7) = −0.25, f(0.8) = 0.23 sign change, f(x) continuous ∴ root M1 A1 (b) f ′(x) = 2 + cos x + 3 sin x x = 0, y = −3, grad = 3 ∴ y = 3x − 3 M1 A1 M1 A1 (c) cos x + 3 sin x = b cos x cos c + b sin x sin c b cos c = 1, b sin c = 3 (c) 8. (−2a, 0) x A1 M1 A1 ∴ b = 12 + 32 = 10 tan c = 3, c = 1.25 (3sf) ∴ a = 2, b = 10 , c = 1.25 (d) SP: 2+ (12) M1 M1 A2 10 cos (x − 1.249) = 0 cos (x − 1.249) = − 2 10 M1 x − 1.249 = π − 0.8861, π + 0.8861 = 2.256, 4.028 x = 3.50, 5.28 (2dp) M1 A2 (14) Total (75) Solomon Press C3I MARKS page 3 Performance Record – C3 Paper I Question no. Topic(s) 1 2 3 4 5 6 7 8 Total rational exponentials differentiation differentiation functions trigonometry functions numerical expressions and methods, logarithms differentiation, trigonometry Marks 5 8 8 8 Student Solomon Press C3I MARKS page 4 9 11 12 14 75 FOR EDEXCEL GCE Examinations Advanced Subsidiary Core Mathematics C3 Paper J 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. C3 Paper J – Marking Guide 1. (a) cos2 x = ( 3 − 1)2 = 3 − 2 3 + 1 = 4 − 2 3 M1 2 (b) cos 2x = 2 cos x − 1 = 2(4 − 2 3 ) − 1 = 7 − 4 3 M1 A1 2(cos y cos 30 − sin y sin 30) = M1 A1 3 2 3 cos y − sin y = 3 2 3 cos y = 3 2 tan y = 2. (a) f(x) = (x − ∴ f(x) ≥ (b) (c) 3. 5 2 sin y − 3 (sin y cos 30 − cos y sin 30) 3 cos y B1 sin y 3 ÷ 5 2 3 2 ) 2 19 4 − 3 5 = 9 4 3 M1 A1 + 7 = (x − 3 2 ) 2 + 19 4 A1 M1 A1 2 fg(x) = f(2x − 1) = (2x − 1) − 3(2x − 1) + 7 ∴ 4x2 − 4x + 1 − 6x + 3 + 7 = 17 2 x2 − 5 x − 3 = 0 (2x + 1)(x − 3) = 0 x = − 12 , 3 x2 + 4x − 4 x4 + x3 − 13x2 x4 − 3x3 + 3x2 4x3 − 16x2 4x3 − 12x2 2 − 4x 2 − 4x 2 x − 3x + 3 ∴ f(x) = x2 + 4x − 4 + M1 A1 M1 A1 + + + + 2x − 5 x 2 − 3x + 3 M1 26x 12x 14x − 17 12x − 12 2x − 5 , A = 4, B = −4, C = 2, D = −5 (a) x = 1 ⇒ y = −2, grad = 5 ∴ grad of normal = − 15 M1 − 15 M1 (x − 1) dx = dy 1 2 sec y 2 tan 0 ≤ y < π ∴ tan y 2 A1 y 2 dy = dx x= π 3 ≥0 ∴ 1 − 1 (3 + 2 cos x) 2 2 dx = dy 1 2 sec y 2 sec 2 y 2 −1 = 1 2 x x2 − 1 × (−2 sin x) = − π 3 M1 A1 M1 A1 sin x 3 + 2 cos x , y = 2, grad = − 14 3 ∴ y − 2 = − 14 3 (x − ) M1 A1 M1 A1 [ 3 3 x + 12y − 24 − π 3 = 0 ] Solomon Press C3J MARKS page 2 (10) M1 dy dx 2 =1÷ = dy dx x x2 −1 (b) A3 M1 A2 ( x − 3x + 3) 5y + 10 = −x + 1 x + 5y + 9 = 0 4. (9) + 26x − 17 2 f ′(x) = 2x + 4 + 2 × ( x − 3 x +23) − (2 x −25) × (2 x − 3) ∴ y+2= (8) M1 A1 = g(11) = 21 (a) (b) 1 2 M1 A1 (11) 5. (a) (b) 6. f(x) > 5 B1 2x − 3 y=5+e 2x − 3 = ln (y − 5) x = 12 [3 + ln (y − 5)] M1 M1 ∴ f −1(x) = 1 2 [3 + ln (x − 5)], x ∈ , x > 5 A2 (c) x = f −1(7) = 1 2 (3 + ln 2) M1 A1 (d) f ′(x) = 2e2x − 3 grad = 4 ∴ y − 7 = 4[x − (a) LHS ≡ ≡ 1 2 [ y = 4x + 1 − 2 ln 2 ] (3 + ln 2)] 2cos 2 x sin x + sin 2 x cos x cos 2 x sin x + sin x cos x cos x M1 cos 2 x + sin 2 x sin x cos x A1 ≡ (cos 2 x − sin 2 x ) + sin 2 x sin x cos x M1 ≡ cos 2 x sin x cos x cos x sin x ≡ cot x ≡ RHS A1 cot x = cosec2 x − 7 cot x = 1 + cot2 x − 7 cot2 x − cot x − 6 = 0 (cot x + 2)(cot x − 3) = 0 cot x = −2 or 3 tan x = − 12 or 13 M1 A1 M1 x = π − 0.4636 or 0.32 x = 0.32, 2.68 (2dp) A2 (a) f(x) ≥ 0 B1 (b) = f(0) = 5 M1 A1 (c) fg(x) = f [ln (x + 3)] = 2 ln (x + 3) − 5 ∴ 2 ln (x + 3) − 5 = 3 2 ln (x + 3) = 2, 8 ln (x + 3) = 1, 4 x = e − 3, e4 − 3 M1 (b) (11) M1 ≡ ≡ 7. M1 A1 M1 A1 M1 (11) M1 A1 M1 A1 let h(x) = f(x) − g(x) h(3) = −0.79, f(4) = 1.1 sign change, h(x) continuous ∴ root M1 A1 (e) x1 = 3.396, x2 = 3.428, x3 = 3.430, x4 = 3.431 M1 A2 (f) h(3.4305) = −0.000052, f(3.4315) = 0.0018 sign change, h(x) continuous ∴ root ∴ α = x4 to 4sf M1 A1 (15) Total (75) (d) Solomon Press C3J MARKS page 3 Performance Record – C3 Paper J Question no. Topic(s) Marks 1 2 trigonometry functions 8 9 3 4 6 7 Total rational differentiation functions, trigonometry functions, expressions, differentiation exponentials differentiation and logs, numerical methods 10 11 Student Solomon Press C3J MARKS page 4 5 11 11 15 75 FOR EDEXCEL GCE Examinations Advanced Subsidiary Core Mathematics C3 Paper K 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. C3 Paper K – Marking Guide 1. (a) (b) arctan (x − 2) = − π3 M1 x − 2 = tan (− π3 ) = − 3 M1 x=2− A1 3 2 1 − 2 sin θ − sin θ − 1 = 0 2 sin2 θ + sin θ = 0 sin θ (2 sin θ + 1) = 0 sin θ = 0 or − 12 θ = 0 or − π6 , −π + M1 M1 A1 π 6 θ = − 5π6 , − π6 , 0 2. (a) (b) = 4x ( x + 3)( x − 3) = 4 x − 2( x − 3) ( x + 3)( x − 3) = 2x + 6 ( x + 3)( x − 3) = 2 x−3 A2 2 x+3 − (8) M1 M1 2( x + 3) ( x + 3)( x − 3) = M1 A1 23 − 8 = 0 ∴ (x − 2) is a factor of (x3 − 8) 2 x−2 x + 2x x3 + 0 x2 x3 − 2 x2 2 x2 2 x2 B1 + 4 + 0x − 8 M1 A1 + 0x − 4x 4x − 8 4x − 8 ∴ x3 − 8 = (x − 2)(x2 + 2x + 4) ∴ 3. (a) 3x − 8 x + 4 = ( x − 2)( x 2 + 2 x + 4) (3x − 2)( x − 2) = −x −x 2 = 2x × e + x × (−e ) = xe (2 − x) (c) = (b) cos x × (3 + 2 cos x) − sin x × (−2sin x) (3 + 2 cos x )2 = M1 A2 3cos x + 2 (3 + 2 cos x)2 M1 A1 (ex − 3)(ex − 5) = 0 ex = 3, 5 x = ln 3, ln 5 M1 A1 assume log2 3 is rational B1 ∴ log2 3 = p q (9) M1 A1 where p and q are integers and q ≠ 0 p ⇒ 2q = 3 ⇒ 2p = 3q 2 and 3 are co-prime ∴ only solution is p = q = 0 but q ≠ 0 ∴ contradiction ∴ log2 3 is irrational Solomon Press C3K MARKS page 2 (9) M1 A1 (3 + 2 cos x)2 3cos x + 2 cos 2 x + 2 sin 2 x M1 A1 M1 A1 −x (b) (a) x2 + 2 x + 4 3x − 2 = −cosec2 x2 × 2x = −2x cosec2 x2 = 4. x3 − 8 2 M1 M1 A1 M1 A1 (10) 5. (a) (b) f(x) > 0 y = 3e B1 x−1 x − 1 = ln , x = 1 + ln x 3 , x>0 M1 A2 (c) f(ln 2) = 3eln 2 − 1 = 3e−1eln 2 = 6e−1 gf(ln 2) = g(6e−1) = 30e−1 − 2 (d) f −1g(x) = f −1(5x − 2) = 1 + ln ∴ 1 + ln x= (a) 1 5 5x − 2 3 = 4, M1 A1 A1 5x − 2 3 5x − 2 = e3 3 M1 A1 M1 (3e3 + 2) A1 2x2 + 3 ln (2 − x) = 0 ⇒ 3 ln (2 − x) = −2x2 ln (2 − x) = − 23 x2 2−x= e − 23 x 2 x=2− e − 23 x 2 M1 [ k = − 23 ] x1 = 1.90988, x2 = 1.91212, x3 = 1.91262, x4 = 1.91273 ∴ α = 1.913 (3dp) f(1.9125) = 0.0070, f(1.9135) = −0.020 sign change, f(x) continuous ∴ root (c) f ′ ( x) = 4 x + 3 2− x 3 2− x × (−1) = 4x − = 0, 4x2 − 8x + 3 = 0, x = 12 , 32 (a) (i) 4x = A1 M1 A1 A1 M1 A1 3 2− x 3 2− x , M1 A1 4x(2 − x) = 3 M1 (2x − 3)(2x − 1) = 0 y (12) M1 (b) ∴ 4x − 7. M1 y 3 f −1(x) = 1 + ln , x ∈ 6. y 3 (ii) M1 A1 (13) y (−45, 15) O (−135, −1) B3 x (135, −1) O x M1 A2 (135, −1) (b) 2 2 cos x − 2 2 sin x = R cos x cos α − R sin x sin α R cos α = 2 2 , R sin α = 2 2 , tan α = 1, α = 45 ∴ f(x) = A + 4 cos (x + 45)° (c) (d) ∴ R= 8+8 = 4 3 3 + 4 cos (x + 45) = 0, M1 A1 B1 B1 cos (x + 45) = − 3 4 x + 45 = 180 − 41.4, 180 + 41.4 = 138.6, 221.4 x = 93.6, 176.4 (1dp) M1 M1 A2 (14) Total (75) Solomon Press C3K MARKS page 3 Performance Record – C3 Paper K Question no. Topic(s) Marks 1 trigonometry 8 2 3 4 6 7 Total rational differentiation exponentials functions numerical functions, expressions and methods, trigonometry logarithms, differentiation proof 9 9 10 Student Solomon Press C3K MARKS page 4 5 12 13 14 75 FOR EDEXCEL GCE Examinations Advanced Subsidiary Core Mathematics C3 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 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. C3 Paper L – Marking Guide 1. (a) 2( x − 2) + 1 x−2 f(x) = =2+ 1 x−2 M1 x > 2 ∴ f(x) > 2 (b) ff(x) = f( = 2(2 x − 3) − 3( x − 2) (2 x − 3) − 2( x − 2) = 2. 2x − 3 ) x−2 A1 2( 2xx−−23 ) − 3 2 x −3 −2 x−2 (a) 4x − 3 = ln 2 x = 14 (3 + ln 2) (b) ln (2y − 1) − ln (3 − y) = ln y= (a) (b) 2y −1 3− y =1 M1 A1 y(e + 2) = 3e + 1 M1 A1 dy 6 = 2ex − x dx x = 1, y = 2e, grad = 2e − 6 ∴ y − 2e = (2e − 6)(x − 1) (7) M1 [ y = (2e − 6)x + 6 ] A1 M1 A1 x=0 ⇒ y=6 y = 0 ⇒ (2e − 6)x + 6 = 0 −6 2e − 6 3 × 3− e 3 3− e 9 3− e M1 A1 = ( x − 10)(2 x − 1) − ( x − 8)( x + 4) ( x − 3)( x + 4)(2 x − 1) M1 A1 = x 2 − 17 x + 42 ( x − 3)( x + 4)(2 x − 1) A1 = ( x − 14)( x − 3) ( x − 3)( x + 4)(2 x − 1) 1 2 ×6 x − 14 ( x + 4)(2 x − 1) = 1, = = = M1 A1 x − 14 ( x + 4)(2 x − 1) x − 14 = 2x2 + 7x − 4 2 x + 3x + 5 = 0 b2 − 4ac = 9 − 20 = −11 b2 − 4ac < 0 ∴ no real roots 5. (6) M1 M1 A1 3e + 1 e+2 area = (b) M1 A1 B1 =e x= (a) =x 2x − 3 x−2 f −1(x) = 2y − 1 = e(3 − y), 4. 4 x − 6 − 3x + 6 2x − 3 − 2x + 4 (c) 2y −1 3− y 3. = M1 tan x + tan 45 − tan x 1 − tan x tan 45 tan x + 1 = 4 + tan x 1 − tan x M1 A1 M1 A1 M1 A1 =4 A1 M1 A1 tan x = −4 ± 16 + 12 = −2 ± M1 7 x = 180 − 77.9, −77.9 or 32.9, −180 + 32.9 x = −147.1, −77.9, 32.9, 102.1 (1dp) Solomon Press C3L MARKS page 2 (9) M1 tan x + 1 = (4 + tan x)(1 − tan x) tan2 x + 4 tan x − 3 = 0 2 (8) B1 M1 A2 (9) 6. (a) y y = 3x + 5a B3 y = x − a (0, 5a) B3 O ( − 53 a, 0) (a, 0) (0, −a) (−a, 0) (b) x ⇒ x = − 32 a −x − a = 3x + 5a M1 A1 −x − a = −(3x + 5a) ⇒ x = −2a, 7. (a) x 2 cos x ≡ cos2 x 2 − sin2 cos x ≡ (1 − sin2 cos x ≡ 1 − 2 sin2 LHS ≡ tan x 2 2 tan2 tan x 2 8. (a) x 2 x 2 x 2 M1 A1 (10) ) − sin2 M1 x 2 M1 x 2 A1 1 − (1 − 2sin 2 2x ) M1 2sin 2x cos 2x 2sin 2 ≡ (c) x = −2a, − a cos (A + B) ≡ cos A cos B − sin A sin B let A = B = (b) 3 2 2sin x 2 x cos 2x 2 = 2 sec2 x 2 − tan = −1 or x 2 x 2 sin 2x ≡ tan x 2 ≡ RHS − 5, tan x 2 = 2(1 + tan2 − 3 = 0, (2 tan ≡ cos 2x x 2 − 3)(tan M1 A1 x 2 x 2 )−5 M1 + 1) = 0 M1 3 2 A1 = 135 or 56.310 B1 x = 112.6° (1dp), 270° A2 dy = 2 × e−x + (2x + 3) × (−e−x) = −(2x + 1)e−x dx SP: −(2x + 1)e−x = 0 1 x = − 12 ∴ ( − 12 , 2e 2 ) (12) M1 A1 M1 A1 (b) x = 0, y = 3, grad = −1, grad of normal = 1 ∴ y=x+3 (c) x + 3 = (2x + 3)e−x x + 3 − (2x + 3)e−x = 0 let f(x) = x + 3 − (2x + 3)e−x f(−2) = 8.4, f(−1) = −0.72 sign change, f(x) continuous ∴ root M1 A1 M1 M1 A1 (d) x1 = −1.1619, x2 = −1.2218, x3 = −1.2408, x4 = −1.2465 = −1.25 (2dp) M1 A2 (e) f(−1.255) = 0.026, f(−1.245) = −0.016 sign change, f(x) continuous ∴ root M1 A1 (14) Total (75) Solomon Press C3L MARKS page 3 Performance Record – C3 Paper L Question no. Topic(s) Marks 1 2 3 4 5 6 7 8 Total functions exponentials differentiation rational trigonometry functions trigonometry differentiation, and expressions numerical logarithms methods 6 7 8 9 9 Student Solomon Press C3L MARKS page 4 10 12 14 75