Foundation June 2018 Paper 2 Q21
21
Diagram NOT accurately drawn
Work out the value of \(x\).
Give your answer correct to 3 significant figures.
(3)
| Scheme | Marks |
|---|---|
| \(\cos 52 = \dfrac{12.6}{x}\) or \(\sin 38 = \dfrac{12.6}{x}\) | M1 |
| \((x =) \dfrac{12.6}{\cos 52}\) or \(\dfrac{12.6}{\sin 38} \left(= \dfrac{12.6}{0.61566\ldots}\right)\) or | M1 |
| 20.5 | A1 |
| (3) | |
| (3 marks) |
Notes
M1: Or use of tan to find horizontal side 12.6 × tan 52 or \(\dfrac{12.6}{\tan 38}\) (=16.12...) and a correct first stage to find \(x\) eg \(x^2 = 12.6^2 + \text{``}{16.12\ldots}\text{''}^2\) or \(\sin 52 = \dfrac{\text{``}{16.12\ldots}\text{''}}{x}\) oe
Allow correct first stage of sine rule
M1: Accept decimal correct to at least 3SF
Or \((x =) \sqrt{12.6^2 + \text{``}{16.12\ldots}\text{''}^2}\) or \((x =) \dfrac{\text{``}{16.12\ldots}\text{''}}{\sin 52}\)
Allow rearranged (\(x\) = ) sine rule
A1: 20.4 – 20.5