Higher June 2019 Paper 1 Q27
27 Angle \(x\) is acute.
\(\cos x = \sin 60^\circ \times \tan 30^\circ\)
Work out the size of angle \(x\).
You must show your working. [3 marks]
| Answer | Mark | Comments |
|---|---|---|
| \(\sin 60^\circ = \dfrac{\sqrt{3}}{2}\) or \(\tan 30^\circ = \dfrac{\sqrt{3}}{3}\) or \(\dfrac{1}{\sqrt{3}}\) or \(\tan 30^\circ \left(= \dfrac{\sin 30}{\cos 30}\right) = \dfrac{1/2}{\sqrt{3}/2}\) | M1 | oe may be in a table may be implied by position in multiplication |
| \(\dfrac{\sqrt{3}}{2} \times \dfrac{1}{\sqrt{3}} = \dfrac{1}{2}\) or \(\cos x = \dfrac{1}{2}\) or \((x =)\ \cos^{-1}\dfrac{1}{2}\) | M1dep | oe works out the value of \(\cos x\) as a fraction or decimal with no surd values |
| 60 with M2 awarded | A1 |
Additional guidance
\(\cos x = 60\) does not score the final mark