| Exam Board | WJEC |
|---|---|
| Module | Unit 3 (Unit 3) |
| Year | 2018 |
| Session | June |
| Marks | 3 |
| Paper | Download PDF ↗ |
| Mark scheme | Download PDF ↗ |
| Topic | Small angle approximation |
| Type | Solve equation using small angle approximation |
| Difficulty | Standard +0.3 This question requires knowledge of small angle approximations (sin x ≈ x, cos x ≈ 1 - x²/2) and solving a resulting quadratic equation. While it involves multiple steps, the technique is standard for C3/C4 level and the question clearly signposts the method to use, making it slightly easier than average. |
| Spec | 1.05e Small angle approximations: sin x ~ x, cos x ~ 1-x^2/2, tan x ~ x |
Use small angle approximations to find the small negative root of the equation
$$\sin x + \cos x = 0.5.$$ [3]
\hfill \mbox{\textit{WJEC Unit 3 2018 Q7 [3]}}