| Exam Board | OCR |
|---|---|
| Module | C2 (Core Mathematics 2) |
| Marks | 4 |
| Paper | Download PDF ↗ |
| Mark scheme | Download PDF ↗ |
| Topic | Sine and Cosine Rules |
| Type | Algebraic side lengths |
| Difficulty | Standard +0.3 This is a straightforward application of the cosine rule with algebraic side lengths. Students must set up the equation correctly and solve a quadratic, but the algebra is routine and the context is standard for C2. Slightly above average difficulty due to the algebraic manipulation required, but still a typical textbook exercise. |
| Spec | 1.05b Sine and cosine rules: including ambiguous case |
2.
The diagram shows triangle $P Q R$ in which $P Q = x , P R = 7 - x , Q R = x + 1$ and $\angle P Q R = 60 ^ { \circ }$.
Using the cosine rule, find the value of $x$.\\
\hfill \mbox{\textit{OCR C2 Q2 [4]}}