| Exam Board | OCR MEI |
|---|---|
| Module | C4 (Core Mathematics 4) |
| Year | 2008 |
| Session | June |
| Marks | 7 |
| Paper | Download PDF ↗ |
| Mark scheme | Download PDF ↗ |
| Topic | Standard trigonometric equations |
| Type | Double angle equations requiring identity expansion and factorisation |
| Difficulty | Moderate -0.3 This is a straightforward double angle equation requiring the standard substitution cos 2θ = 1 - 2sin²θ, leading to a quadratic in sin θ. The solutions are standard angles (π/6, 5π/6, 3π/2) that students should recognize. Slightly easier than average due to being a routine application of a standard technique with no conceptual surprises. |
| Spec | 1.05l Double angle formulae: and compound angle formulae1.05o Trigonometric equations: solve in given intervals |
| Answer | Marks | Guidance |
|---|---|---|
| Grid shown: Row 2 correct | B1 | Rest correct |
Grid shown: Row 2 correct | B1 | Rest correct | B1 | Many possible answers3 Solve the equation $\cos 2 \theta = \sin \theta$ for $0 \leqslant \theta \leqslant 2 \pi$, giving your answers in terms of $\pi$.
\hfill \mbox{\textit{OCR MEI C4 2008 Q3 [7]}}