| Exam Board | Edexcel |
|---|---|
| Module | C2 (Core Mathematics 2) |
| Marks | 9 |
| Paper | Download PDF ↗ |
| Topic | Standard trigonometric equations |
| Type | Quadratic in sin²/cos²/tan² |
| Difficulty | Moderate -0.8 This is a routine C2 trigonometric equation requiring the standard identity cos²θ = 1 - sin²θ to convert to a single trigonometric function, then basic algebraic manipulation and calculator work. The 'show that' part is scaffolded (2 marks), and solving involves straightforward steps with no conceptual challenges beyond standard technique application. Easier than average for A-level. |
| Spec | 1.05j Trigonometric identities: tan=sin/cos and sin^2+cos^2=11.05o Trigonometric equations: solve in given intervals |
\begin{enumerate}[label=(\alph*)]
\item Show that the equation
$3 \sin^2 \theta - 2 \cos^2 \theta = 1$
can be written as
$5 \sin^2 \theta = 3$.
[2]
\item Hence solve, for $0° \leq \theta \leq 360°$, the equation
$3 \sin^2 \theta - 2 \cos^2 \theta = 1$,
giving your answer to 1 decimal place.
[7]
\end{enumerate}
\hfill \mbox{\textit{Edexcel C2 Q4 [9]}}