Foundation June 2019 Paper 1 Q18
18 Here is a right-angled triangle.
Not to scale
Work out the value of \(x\). [3]
| Answer | Marks | Part marks and guidance |
|---|---|---|
| 21.6[3...] | 3 | Accept \(6\sqrt{13}\) as final answer for 3 marks M2 for \(\sqrt{12^2 + 18^2}\) soi by \(\sqrt{468}\) or M1 for \(12^2 + 18^2\) implied by 468 See appendix |
Appendix
Q18 Alternative
M1 for \(\tan\theta = \dfrac{12}{18}\) \(\theta = 33.69..\) and
M1 for \(x = \dfrac{18}{\cos\theta}\) or \(x = \dfrac{12}{\sin\theta}\)
OR
M1 for \(\tan\alpha = \dfrac{18}{12}\) \(\alpha = 56.3099\) and
M1 for \(x = 12 \div \cos\alpha\) \(\dfrac{12}{\cos\alpha}\) or \(x = 18 \div \sin\alpha\) \(\dfrac{18}{\sin\alpha}\)