| Part | Scheme | Marks | AOs |
|---|---|---|---|
| (a) | x-transformation: −4 → −4 × ½ = −2 ; y-transformation: 5 → 5 × 4 = 20 | M1 | 1.1b |
| Image point: (−2, 20) | A1 | 1.1b | |
| (b) | x-transformation: −4 → −4 − 3 = −7 ; y-transformation: 5 → 5 − 2 = 3 | M1 | 1.1b |
| Image point: (−7, 3) | A1 | 1.1b |
| Part | Scheme | Marks | AOs |
|---|---|---|---|
| (a) | f(1.1) = e2(1.1) − 1 + 3(1.1) − 7 = e1.2 + 3.3 − 7 = −0.380... < 0 f(1.2) = e2(1.2) − 1 + 3(1.2) − 7 = e1.4 + 3.6 − 7 = 0.655... > 0 |
M1 | 1.1b |
| States there is a change of sign and the function f(x) is continuous on [1.1, 1.2], concluding that there is a root α in the interval. | A1* | 2.4 | |
| (b) | x2 = ½(1 + ln(7 − 3(1.1))) = ½(1 + ln(3.7)) = 1.15423... ➔ awrt 1.1542 | M1 | 1.1b |
| x3 = 1.1293..., x4 = 1.1415... ➔ continues iterations to obtain α = 1.1383 (correct to 4 d.p.) | A1 | 1.1b |
| Part | Scheme | Marks | AOs |
|---|---|---|---|
| (a) | dydx = 3x² − 4x + 5 | B1 B1 |
1.1b 1.1b |
| (b) | Substitute x = 2 into dydx: m = 3(2)² − 4(2) + 5 = 9 | M1 | 1.1b |
| Find the y-coordinate at x = 2: y = 2³ − 2(2)² + 5(2) − 7 = 3 ➔ P(2, 3) | B1 | 1.1b | |
| Equation of tangent: y − 3 = 9(x − 2) ➔ y = 9x − 15 | A1 | 1.1b |
| Part | Scheme | Marks | AOs |
|---|---|---|---|
| (a) | f(x) ≥ −2 (or y ≥ −2) | B1 | 1.1b |
| (b) | Evaluate f(2) = 3(2)² − 2 = 10 | M1 | 1.1b |
| Substitute x = 10 into g(x): g(10) = 5(10) − 110 − 4 = 496 | A1 | 1.1b | |
| (c) | Let y = 5x − 1x − 4 ➔ y(x − 4) = 5x − 1 ➔ xy − 4y = 5x − 1 | M1 | 1.1b |
| xy − 5x = 4y − 1 ➔ x(y − 5) = 4y − 1 ➔ x = 4y − 1y − 5 | A1 | 2.1 | |
| g−1(x) = 4x − 1x − 5, Domain: x ∈ ℝ, x ≠ 5 | A1 | 2.5 |
| Part | Scheme | Marks | AOs |
|---|---|---|---|
| (a) | Maximum height is 10 m (since the maximum value of sin(θ) is 1) | B1 | 3.4 |
| (b) | Set y = 5: 10 sin(t²4) = 5 ➔ sin(t²4) = 0.5 | M1 | 3.1b |
| Finds second positive principal solution: t²4 = π − π6 = 5π6 | M1 | 2.1 | |
| Solve for t: t² = 20π6 = 10π3 ➔ t = √10π3 ≈ 3.236... seconds | dM1 | 1.1b | |
| Substitute t into x: x = 100 × √3.236... = 179.889... m ➔ awrt 179.9 m | A1 | 1.1b |
| Part | Scheme | Marks | AOs |
|---|---|---|---|
| (a) | Attempts integration of the form k ln(7x + 1) | M1 | 1.1b |
| ∫ 37x + 1 dx = 37 ln(7x + 1) (condone missing constant) | A1 | 1.1b | |
| (b) | Apply boundaries: 37 ln(7p + 1) − 37 ln(15) = 67 | M1 | 1.1b |
| Divide by 37: ln(7p + 1) − ln(15) = 2 | M1 | 1.1b | |
| Merge logarithms: ln(7p + 115) = 2 ➔ 7p + 115 = e² | dM1 | 1.1b | |
| Solve for p: 7p + 1 = 15e² ➔ p = 15e² − 17 | A1 | 2.1 |
| Part | Scheme | Marks | AOs |
|---|---|---|---|
| (a) | Area of minor sector BOC = ½ r² θ ; Area of triangle BOC = ½ r² sin θ Area of region R₁ (segment BC) = ½ r² (θ − sin θ) |
M1 | 2.1 |
| Area of region R₂ = Semicircle − Sector BOC − Triangle AOB Area R₂ = ½ π r² − ½ r² θ − ½ r² sin(π − θ) |
M1 | 3.1a | |
| Simplify using sin(π − θ) = sin θ: R₂ = ½ r² (π − θ − sin θ) | B1 | 1.1b | |
| Set R₁ = 2R₂: ½ r² (θ − sin θ) = 2 [ ½ r² (π − θ − sin θ) ] θ − sin θ = 2(π − θ − sin θ) ➔ θ − sin θ = 2π − 2θ − 2 sin θ |
dM1 | 1.1b | |
| Collects terms to show: sin θ + 3θ − 2π = 0 ★ | A1* | 2.1 | |
| (b) | Let f(θ) = sin θ + 3θ − 2π ➔ f′(θ) = cos θ + 3 Evaluate at θ₁ = 1.3: f(1.3) = sin(1.3) + 3(1.3) − 2π ≈ −1.420... f′(1.3) = cos(1.3) + 3 ≈ 3.267... |
M1 | 1.1b |
| θ2 = 1.3 − −1.420...3.267... ≈ 1.7348... ➔ awrt 1.735 | A1 | 1.1b |
| Part | Scheme | Marks | AOs |
|---|---|---|---|
| (a) | limδx → 0 ∑x = 03 x e2x δx = 30∫ x e2x dx | B1 | 1.1b |
| (b) | Integration by parts: u = x ➔ du = dx ; dv = e2x dx ➔ v = ½ e2x ∫ x e2x dx = ½ x e2x − ∫ ½ e2x dx = ½ x e2x − ¼ e2x |
M1 A1 |
2.1 1.1b |
| Substitute boundaries: [ ½ x e2x − ¼ e2x ]03 = ( ³/₂ e⁶ − ¼ e⁶ ) − ( 0 − ¼ e⁰ ) | dM1 | 1.1b | |
| Result = ⁵/₄ e⁶ + ¼ ➔ (A = ⁵/₄, B = ¼) | A1 | 1.1b |
| Part | Scheme | Marks | AOs |
|---|---|---|---|
| (a) |
(cos θ + sin θ)(cosec θ − sec θ) = (cos θ + sin θ)(1/sin θ − 1/cos θ) = (cos θ + sin θ) cos θ − sin θsin θ cos θ = cos² θ − sin² θsin θ cos θ |
M1 | 2.1 |
| = cos 2θ½ sin 2θ = 2 cot 2θ ➔ k = 2 | A1 | 1.1b | |
| (b) | Apply identity: 5(2 cot 2x) = 4 cosec²(2x) ➔ 10 cos 2xsin 2x = 4sin² 2x | M1 | 1.1b |
| Multiply across: 10 cos 2x sin 2x = 4 ➔ 5(2 sin 2x cos 2x) = 4 ➔ 5 sin 4x = 4 | M1 | 1.1b | |
| sin 4x = 0.8 ➔ 4x = 53.13°, 126.87°, −233.13°, −306.87° | dM1 | 1.1b | |
| Solve for x: x = −76.7°, −58.3°, 13.3°, 31.7° | A1 A1 |
1.1b 1.1b |
| Part | Scheme | Marks | AOs |
|---|---|---|---|
| (a) | At x = 2: y = 7(2)√3(2)² + 4 = 14√16 = 3.5 ➔ P(2, 3.5) | B1 | 1.1b |
| Differentiate y = 7x(3x² + 4)−½ using derivative rules: dydx = 7√3x² + 4 − 7x(½)(3x² + 4)−½(6x)3x² + 4 = 28(3x² + 4)1.5 |
M1 A1 |
1.1b 1.1b |
|
| At x = 2: dydx = 28161.5 = 2864 = 716 | M1 | 2.1 | |
| Normal gradient = −167 | M1 | 1.1b | |
| Normal line: y − 3.5 = −167(x − 2) ➔ 32x + 14y − 113 = 0 ★ | A1* | 1.1b | |
| (b) | Set x = 0 ➔ 14y = 113 ➔ y = 11314 (or \(8.07\)) | B1 | 1.1b |
| (c) | Perform integration via reverse chain rule / substitution: ∫ 7x(3x² + 4)−½ dx = 73 (3x² + 4)½ |
M1 A1 |
1.1b 1.1b |
| Calculate Curve Area: [ 73 √3x² + 4 ]02 = 283 − 143 = 143 | B1 | 1.1b | |
| Calculate Trapezium Area: 20∫ (−167 x + 11314) dx = 817 | dM1 | 3.1a | |
| Combined Area of R = 817 − 143 = 14521 | A1 | 1.1b |
| Part | Scheme | Marks | AOs |
|---|---|---|---|
| (a) | R cos(θ + α) = R cos θ cos α − R sin θ sin α R cos α = 4 ; R sin α = 13 ➔ R = √4² + 13² = √185 |
B1 | 1.1b |
| tan α = 134 ➔ α = awrt 1.272 | M1 | 1.1b | |
| Result: √185 cos(θ + 1.272) | A1 | 1.1b | |
| (b) | Minimum daily consumption is D = 30 − √185 = awrt 16.4 GWh | B1ft | 3.4 |
| (c) | Minimum consumption occurs when cos(π t12 + 0.2 + 1.272) = −1 | M1 | 3.4 |
| π t12 + 1.472 = π ➔ π t12 = π − 1.472 = 1.670... ➔ t = 6.377 hours | dM1 | 2.1 | |
| Convert to clock time: 6.377 hours = 6 hours 23 mins after midnight ➔ 06:23 | A1 A1 |
1.1b 3.2a |
|
| (d) | Energy usage significantly varies between weekdays and weekends (or due to seasonal temperature shifts) which are not accounted for by this simplified 24-hour model. | B1 | 3.5b |
| Part | Scheme | Marks | AOs |
|---|---|---|---|
| (a) | Draws reciprocal curve branches in quadrants 1 and 3 correctly. | B1 | 1.1b |
| Draws V-shaped modulus curve with vertex on the positive x-axis. | B1 | 1.1b | |
| Coordinates written clearly as (q/p, 0) and (0, q). | A1 | 1.1b | |
| (b) | Right-hand branch equation: kx = px − q ➔ px² − qx − k = 0 | M1 | 3.1a |
| Right discriminant: b² − 4ac = (−q)² − 4(p)(−k) = q² + 4pk Since p, k > 0, discriminant is always positive, yielding exactly 1 positive root intersection. |
A1 | 2.4 | |
| Left-hand branch equation: kx = q − px ➔ px² − qx + k = 0 | dM1 | 1.1b | |
| Two roots required for exactly 3 total intersections: b² − 4ac > 0 | A1 | 1.1b | |
| Deduces correct inequality: q² − 4pk > 0 ➔ 0 < k < q²4p | A1 | 2.2a |
| Part | Scheme | Marks | AOs |
|---|---|---|---|
| (a) | Write out ratio: r = √2 cos θsin θ and r = √3 cos θ cot θ√2 cos θ = √3 cot θ√2 | M1 | 2.1 |
| Equate both ratios: √2 cos θsin θ = √3 cos θ√2 sin θ | dM1 | 1.1b | |
| Simplify equation: 2 = √3 cos θ ➔ cos θ = √32 ➔ θ = π6 ★ | A1* | 1.1b | |
| Evaluate ratio: r = √2 cos(π/6)sin(π/6) = √6 | A1 A1 |
1.1b 1.1b |
|
| (b) | Find terms: u₃ = sin(π/6) = 0.5 u₂ = u₃r = 12√6 = √612 ; u₁ = u₂r = 112 |
M1 A1 |
1.1b 1.1b |
| Add terms: Sum = 112 + √612 + 612 | dM1 | 1.1b | |
| Sum = 7 + √612 | A1 | 1.1b |
| Part | Scheme | Marks | AOs |
|---|---|---|---|
| (a) | Separate variables: ∫ 1x dx = ∫ (A − t) dt | M1 | 2.1 |
| Integrate: ln(x) = At − t²/2 + c | A1 | 1.1b | |
| Exponentiate: x = D e(At − t²/2) | dM1 | 1.1b | |
| Substitute boundaries: t = 0, x = 0.3 ➔ D = 0.3 | A1 | 3.4 | |
| Substitute boundary: t = 4, x = 21 ➔ 21 = 0.3 e(4A − 8) ➔ 70 = e(4A − 8) | dM1 | 3.4 | |
| Solve for A: 4A − 8 = ln 70 ➔ A = 2 + ¼ ln 70 ★ | A1* | 1.1b | |
| (b) | Using model: Maximum occurs when dx/dt = 0 ➔ t = A | M1 | 3.1b |
| Evaluate: x = 0.3 e(A² − A²/2) = 0.3 e(A²/2) | A1 | 1.1b | |
| Substitute A ≈ 3.062... ➔ x ≈ 32.607... ➔ awrt 32.6 | A1 | 1.1b | |
| (c) | Set x = 0.1 ➔ 0.3 e(At − t²/2) = 0.1 ➔ At − t²/2 = −ln 3 | M1 | 3.4 |
| Rearrange to quadratic: t² − 2At − 2 ln 3 = 0 ➔ T = A + √A² + 2 ln 3 ≈ 6.464 hours | A1 | 1.1b |
| Part | Scheme | Marks | AOs |
|---|---|---|---|
| - | Assume that a and b are both odd positive integers. Let a = 2m + 1 and b = 2n + 1, where m, n are non-negative integers. |
M1 | 2.1 |
| Expand and sum squares: a² + b² = (2m + 1)² + (2n + 1)² = 4m² + 4m + 1 + 4n² + 4n + 1 |
M1 | 2.2a | |
| Factor out 2: a² + b² = 2(2m² + 2m + 2n² + 2n + 1) This demonstrates a² + b² is even, so c² must be even, which implies c is even. |
dM1 | 1.1b | |
| Let c = 2k ➔ c² = (2k)² = 4k², which is a multiple of 4. However, a² + b² is of the form 4(m² + m + n² + n) + 2, leaving a remainder of 2 when divided by 4. Therefore, a² + b² ≠ c². This is a contradiction, hence a and b cannot both be odd. |
A1 | 2.4 |