Tab 4
fA-Level Maths — Exam Revision Notes Questions · Marks
@milo thank you for your help np
Question | Marks | Answer / Key Steps |
Q1 — Translation of Co-ordinates P(−4, 5) a) 4f(2x) b) f(x+3) − 2 | 4 | a) (−2, 20) → 2 marks b) (−7, 3) → 2 marks |
Q2 — Approximation / Root Finding f(x) = c·x³ + 3x − 2 A) Show root lies in [1.1, 1.2] B) Find x₂ Bi) Find A | a)2 Total 5 | A) f(1.1) and f(1.2) change sign → continuous → root in interval B) x₂ =1.158(apply Newton–Raphson or iteration) Bi) a =1.138 (value from iteration) |
Q3 — Differentiation f(x) = (given function) Find dy/dx, then use coordinate (2, 3) | 5d | dy/dx = (differentiated expression) Tangent: y = 9x − 15 |
Q4 — Functions g(x) = (5x − 1)/(x − 4) f(x)=3x^2 -2 a) Minimum point of f(x) b) Find gf(x) when x=2? c) Find g⁻¹(x) | 5 | a) f≥ −2 b) 49/6 c) g⁻¹(x) = (4x − 1)/(x − 5) |
Q5 — Helicopter Parametric x = 100√t, y = 10 sin(t²/4) a) Maximum vertical height b) Horizontal distance at max height of 5 m | 5 -someone said 6 | a) 10 m b) 180 m |
Q6 — Integration ∫₂ᵖ [3 / (7x + 1)] dx = 6/7, p > 2 | 5 | P = (15e² − 1) / 7 |
Q7 — Area of Semicircle Segment R₁ = 2R₂ (given) a) Show: p·sinθ + q·θ − 2π = 0 b) 1st approx α = 1.3; find 2nd approx via Newton–Raphson | 7 | a) p = 1, q = 3 → sinθ + 3θ − 2π = 0 Area of segment: A = ½r²(θ − sinθ) R₁ = 2R₂ leads to θ − sinθ = 2(π − θ) − 2sin(π − θ) sin(π − θ) = sinθ → simplifies to 3θ + sinθ − 2π = 0 ✓ b) f(a) = 3a + sin(a) − 2π f′(a) = 3 + cos(a) Apply NR: aₙ₊₁ = aₙ − f(aₙ)/f′(aₙ) |
Q8 — Integration (Area) x-coord of P = 2 (given) | 5 Someone said 6 | Answer: 5/4 · e⁶ + ¼ |
Q9 — Trig Identity (sinθ + cosθ)(cosecθ − secθ) = k·cot2θ a) Find k b) Solve (sinx + cosx)(cscx − secx) = 4csc²(2x) for −90° < x < 90° | a)3 or 4? 2 people said total 8 | a) k = 2 cosecθ − secθ = (cosθ − sinθ)/(sinθ cosθ) = 2(cosθ − sinθ)/sin2θ Full product = 2cos2θ/sin2θ = 2cot2θ ✓ b) Note: equation reduces to sin4x = 4 (no solution) Likely intended: 2csc²(2x) → check original paper |
Q10 — Modulus Graph a) Draw modulus graph b) Find range of k using y = k/x | 7 | Intercept = q, vertex = q/p k/x intersects negative-gradient region twice: 0 < k < q²/(4p) |
Q11 — Curve & Area y_C = 7x / √(3x² + 4) a) Equation of line L: ax + by + c = 0 b) y-coord of point Q c) Area of bounded region R | 10 | a) 14y + 32x − 133 = 0 (intercept 113/14) c) ∫₀² (−16x/7 + 113/14 − 7x/√(3x²+4)) dx = 145/21 |
Q12 — Harmonic Form a) 4cosx − 13sinx = R·cos(x + α) b) D = 30 + 4cos(πt/12 + 0.2) − 13sin(πt/12 + 0.2) bi) Find minimum value of D bii) Find time T at minimum c) Why can't this model be used year-round? | a:3 b:1 c:4 d:1 Someone said 7 | a) R = √185, α = 1.272 bi) Minimum D = 30 − √185 ≈ 16.4 (stated as ~2.7 in notes) bii) t ≈ 6:23 c) Model is periodic / doesn't account for seasonal variation |
Q13 — Geometric Series u₃ = sinθ, u₄ = √2·cosθ, u₅ = √3·cotθ a) Find common ratio r (exact) b) Find sum of terms 1, 2 and 3 | 7 a)4 | a) θ = π/6, r = √6 b) uₙ = (1/12)(√6)ⁿ⁻¹ S = u₁ + u₂ + u₃ = 1/12(1 + √6 + 6) = (7 + √6)/12 |
Q14 — Differential Equation dx/dt = x(A − t) a) Solve (exact value) b) Find maximum value of x c) Find time T when x returns to start | 11 (4+3+3 approx) | a) x = 0.3·e^(2t + t/4·ln70 − t²/2) b) x_max ≈ 32.6 when t = A c) T ≈ 6.46 |
Q15 — Proof by Contradiction Given a² + b² = c² Prove a and b cannot both be odd | 4 | Let a = 2m+1, b = 2n+1 (both odd) a² + b² = 4m²+4m+1 + 4n²+4n+1 = 4m²+4m+4n²+4n+2 = 4(m²+m+n²+n) + 2 → even but ≢ 0 (mod 4) So c² ≡ 2 (mod 4). But squares are 0 or 1 (mod 4). Contradiction → a and b cannot both be odd ✓ |
currently total marks ≈97? Don’t know exactly how many marks each question and part is worth
Copy and pasted the ruined doc into claude and it gave me this back ^^^^ should be fine now
Is it okay if i delete everything below the message im typing rn??
~
Can i delete everything below???? We have it all fixed above, besides images
Google docs doesnt have collapsable headers gng i dont see why we still want the bit below
question | marks | answer |
1 Translation of co-ordinates P(-4,5)
| 4 | (-2,20) → 2 marks (-7,3) → 2 marks |
2 Approximation A)Show root lies in 1.1-1.2 B)FIND X2 Bi) FIND A | f(1.1) f(1.2) change in sign continuous x2= a= | |
3 differentiation question f(x)= dy/dx= coordinate(2, 3) Y = 9x-15 | 5 | |
4 Function f(x) = g(x) = b) c) find g^-1(x) | 5 | a)F>-2 b) 49/6 C)Y=(4x-1)/x-5 |
5 Helicopter parametric X = 100√ t y = 10sin(t2/4)
| 5x |
b)180m |
6 p ∫ from 2 to p [3/(7x + 1)] dx = 2 | 5 | P = (15e^2 - 1)/7 |
7 Area of semicircle segment R1 = 2R2 (given) a “Show psinθ + qθ - 2π = 0 b “1st approximation for α = 1.3. Use newton raphson method to find 2nd approximation for α “ | 7 | a) 1sinθ + 3θ - 2π = 0 Aka p = 1 , q = 3 To solve, use areausearea of segment A = (θ-sinθ)r2/2 R1 = (θ-sinθ)r2/2 = 2R2 R2 = (π - θ - sin(π - θ))r2/2 Therefore (θ-sinθ)r2/2 = 2(π - θ - sin(π - θ))r2/2 This simplifies to (θ-sinθ) = 2π - 2θ - 2sin(π - θ) sin(-θ + π) = sin(θ) Therefore θ-sinθ = 2π - 2θ - 2sinθ Rearrange to 3θ + sinθ - 2π = 0 b) For Newton Raphson, f(x) = 0 Since 3a + sin(a) - 2π = 0 We can say: f(a) = 3a + sin(a) - 2π f’(a) = 3+cos(a) Apply NR method to |
8 Integration x of P = 2 (given) Wrong q thats q 11 aight | 5 | 5/4 ( e^6) + ¼ |
9 Trig equation (sinθ+cosθ)(cosecθ-secθ)=kcot2θ 2nd Part of Question: (sinx + cosx)(cscx - secx) = 4csc2 (2x) For this u made 4cosec2^(2x)=2cot(2x) then make the coesec^2(2x) cot^2x from the identity sin^2 + cos^2=1 by dividing by sin^2 ^^ I think this function is wrong, because it gives the result sin4x = 4 Might have been 2csc squared then The values in the student room ai markscheme is what i got -90o < x < 90o Solve for x | k=2 Cscθ = 1/sinθ Secθ = 1/cosθ Multiply top and bottom, so the left bracket = ((cosθ - sinθ)/(sinθcosθ)) = 2(cosθ - sinθ)/(2sinθcosθ) = 2(cosθ - sinθ)/(sin2θ) Therefore total equation is: ( (cosθ + sinθ) ⨉ 2(cosθ - sinθ) ) / (sin2θ) = 2(cos2θ - sin2θ) / (sin2θ) = 2(cos2θ) / (sin2θ) = 2 cot2θ Therefore k = 2 [error somewhere] Second part of the Question: (sinx + cosx)(cscx - secx) = 4csc22x [given] (sinx + cosx)(cscx - secx) = 2cot2x [substitution from part a] Therefore, 4csc22x = 2cot2x Csc22x = 1/sin22x Cot2x = cos2x/sin2x Therefore 4 = 2sin2(2x)cos(2x)/sin2x 4 = 2sin(2x)cos(2x) 4 = sin4x ?? | |
10 (a) Drawing modulus graph (b) range of k using y=k/x | 7 |
|
11 yC = 7x / root(3x2 + 4) a) find equation of line L in form ax + by + c = 0 b) find y co-ordinate of point Q b) find area of bounded region R | 10 | 14y-32x-113 Was it not 14y+32x-133=0 Intercept 113/14 ∫₀² (−16x/7 + 113/14 − 7x/√(3x² + 4)) dx = 145/21 (6.904…) was the answer not |
12) Harmonic Form a) 4cosx - 13sinx = Rcos(x+a) b) D = 30 + 4cos(πt/12 + 0.2) - 13sin(πt/12 + 0.2) bi) find MINIMUM bii) find time T @ minimum | 6? How many marks was this Part a, 3 marks B,1 C, 4 D,1 Was c just dy/dx=0 i forgot wha I equated it to -1 so i got shook when u said dy/dx |
a= 1.272
C)2.7 |
13 Geometric series u3 = sinθ u4 = √root2 cosθ u5 = √root3 cotθ a) find the common ratio (r) exact value. b) find the sum of term 1, 2, and 3 | 7 6? 3 and 3 | a=pi/6 Where did 7 come from??? u3 = ar2 u4 = ar3 u5 ar4 Solution to part a) ar2 = sinθ ar3 = √2 cosθ ar4 = root3 cotθ ar3 = rsinθ = root2 cosθ Ar4 = r root2 cosθ = root3 cotθ r = root(6) Solution to part b) |
14. Differential equation | 11 | A x = 0.3e^(2t+t/4 ln70 - t^2/2) B max is like 32.6 when t = A = 32.600522346 |
15 Proof | 4 | Person 1’s Answer: Expand out a^2 and b^2 using 2m+1 and 2n+1 and sum. This gives you 4m^2 + 4m + 4n^2 + 4n + 2 = c^2. c^2 is even, therefore c is even, therefore c = 2p where p is an integer. Therefore c^2 = 4p^2. Factor out 2 on both sides, you get 2m^2 + 2m + 2n^2 + 2n + 1 = 2p^2. Therefore even = odd, therefore contradiction. Person 2’s Answer: Expand out a^2 and b^2 using 2m+1 and 2n+1 and sum. Root this answer. Take out factor of root two. Show inside other root is always odd so can never equal any multiple of root two therefore c is always irrational. |
wait for 10c was it the area between the line/curve and y axis or with the x axis?