Foundation June 2019 Paper 3 Q30
30 Here is a right-angled triangle.
Not drawn accurately
Use trigonometry to work out the size of angle \(x\). [2 marks]
| Answer | Mark | Comments |
|---|---|---|
| Alternative method 1 | ||
| \(\sin x = \dfrac{13}{16}\) or \(\sin^{-1} \dfrac{13}{16}\) | M1 | oe \(\sin x = 0.8125\) |
| 54(.3…) | A1 | |
| Alternative method 2 | ||
| \(\cos x = \dfrac{13}{16}\) or \(\cos^{-1} \dfrac{13}{16}\) and \(90 -\) their [35.6, 36] | M1 | oe |
| 54(.3…) | A1 | |
| Alternative method 3 | ||
| \(\cos x = \dfrac{\sqrt{16^2 - 13^2}}{16}\) or \(\tan x = \dfrac{13}{\sqrt{16^2 - 13^2}}\) | M1 | oe |
| 54(.3…) | A1 | |
Additional guidance
| \(\sin = \dfrac{13}{16}\) or \(\sin \dfrac{13}{16}\) or \(\sin^{-1} = \dfrac{13}{16}\) unless recovered | M0 |
| Answer 54 from scale drawing with no trigonometry | M0A0 |