| Exam Board | OCR MEI |
|---|---|
| Module | C4 (Core Mathematics 4) |
| Year | 2015 |
| Session | June |
| Marks | 7 |
| Paper | Download PDF ↗ |
| Mark scheme | Download PDF ↗ |
| Topic | Addition & Double Angle Formulae |
| Type | Solve equation with sin2x/cos2x by substitution |
| Difficulty | Moderate -0.3 This is a straightforward application of the double angle formula cos(2θ) = 1 - 2sin²(θ), leading to a quadratic in sin(θ). The solving process is routine: substitute the formula, rearrange to standard form, factor or use the quadratic formula, then find angles in the given range. Slightly easier than average as it follows a standard template with no conceptual surprises. |
| Spec | 1.05j Trigonometric identities: tan=sin/cos and sin^2+cos^2=11.05l Double angle formulae: and compound angle formulae1.05o Trigonometric equations: solve in given intervals |
**Question 2:** [2 marks]
Percentage of journey time car A is stationary (load time + transfer time as % of total round trip time from Table 4)2 Express $6 \cos 2 \theta + \sin \theta$ in terms of $\sin \theta$.\\
Hence solve the equation $6 \cos 2 \theta + \sin \theta = 0$, for $0 ^ { \circ } \leqslant \theta \leqslant 360 ^ { \circ }$.
\hfill \mbox{\textit{OCR MEI C4 2015 Q2 [7]}}