CAPE Pure Mathematics Unit 1 · 2022 · Paper 2 · Question 3(d)
Given that \sin A = \frac{1}{3} and A is obtuse, calculate the value of \cos A without using a calculator.
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Practise this questionOther parts of this question
- 3(a)Prove that
\frac{\tan\theta \sin\theta}{1 - \cos\theta} = 1 + \frac{1}{\cos\theta}.[6 marks] - 3(b)Solve the equation
\tan^2\theta - 2\tan\theta = 3for0 \le \theta \le 2\pi.[6 marks] - 3(c)(i)Show that
4\cos\theta + 3\sin\theta = 5\sin(\theta + 0.927^c).[5 marks] - 3(c)(ii)Hence, or otherwise, solve the equation
4\cos\theta + 3\sin\theta = 0.[4 marks]
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