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Maths

Trigonometry

Edexcel Pure 5

A-level Maths (9MA0) · exam-style practice, examiner-report intelligence and the tools that drill it.

Board and spec code confirmed against Edexcel 9MA0 · registry checked 2026-07-11How this checking works

The topic on one screen

  • Radians for anything with calculus or sectors: arc length =rθ= r\theta, sector area =12r2θ= \tfrac{1}{2}r^2\theta.
  • The two identities that solve most equations: sin2x+cos2x=1\sin^2 x + \cos^2 x = 1 and tanx=sinxcosx\tan x = \dfrac{\sin x}{\cos x}.
  • Harmonic form: acosθ+bsinθ=Rcos(θ±α)a\cos\theta + b\sin\theta = R\cos(\theta \pm \alpha) with R=a2+b2R = \sqrt{a^2 + b^2} and tanα=ba\tan\alpha = \dfrac{b}{a} — then max/min and solving become one-liners.
  • Solving in a range: get ALL solutions — draw the CAST diagram or the graph, don't stop at the calculator value.
  • Trig modelling (wheels, tides, stages): amplitude = half the max-min gap, the constant = the midline, period =360k= \dfrac{360}{k} (degrees) or 2πk\dfrac{2\pi}{k} (radians).
  • Small-angle approximations (radians only): sinθθ\sin\theta \approx \theta, tanθθ\tan\theta \approx \theta, cosθ1θ22\cos\theta \approx 1 - \tfrac{\theta^2}{2}.

Where students actually lose marks

In Rcos(θ+α)R\cos(\theta + \alpha) questions, RR must be exact and positive — and the mark scheme wants α\alpha to the stated accuracy. A rounded RR poisons every later part.

June 2024 Paper 1 mark scheme (Q12)

Sector questions mix degrees and radians as a trap: the formulas rθr\theta and 12r2θ\tfrac{1}{2}r^2\theta are RADIAN formulas — using 2.3 rad in a degree formula (or vice versa) voids the method mark.

June 2023 Paper 1 question paper (Q08, angle given in radians)

In trig-equation solving the scheme awards the second solution separately — candidates who only give the principal value routinely drop that mark.

June 2023 Paper 1 mark scheme (general pattern)

Try it — exam-style

Easy
ORIGINAL · after June 2023 Paper 1 Q08

1.

A sector has radius 8 cm and angle 1.2 radians. Find (i) the arc length and (ii) the area of the sector.

(3)

(Total for Question 1 is 3 marks)

Medium
ORIGINAL · after June 2024 Paper 1 Q12

2.

Express 3cosθ4sinθ3\cos\theta - 4\sin\theta in the form Rcos(θ+α)R\cos(\theta + \alpha), where R>0R > 0 and 0<α<900 < \alpha < 90^\circ. Hence state the maximum value of 3cosθ4sinθ3\cos\theta - 4\sin\theta.

(4)

(Total for Question 2 is 4 marks)

Hard
ORIGINAL

3.

Solve 2sin2x+3cosx=32\sin^2 x + 3\cos x = 3 for 0x3600^\circ \le x \le 360^\circ.

(4)

(Total for Question 3 is 4 marks)

Medium
ORIGINAL · after June 2023 Paper 1 Q13

4.

The height of a carriage on a wheel is modelled by H=1210cos(30t)H = 12 - 10\cos(30t)^\circ, with HH in metres and tt in minutes. State (i) the maximum height, (ii) the minimum height, and (iii) the time for one complete revolution.

(3)

(Total for Question 4 is 3 marks)

Questions are written in the style of past Edexcel papers (source shown on each) — never copied from them.

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Drill it properly

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