Trigonometric identitiesAQA A-Level Maths: Mind map

Exam questions on Trigonometric identities

1. The angle $\theta$ is obtuse and $\sin\theta=\frac{5}{13}$.
   Find the exact value of $\sin\theta\cos\theta$.2 marks
2. For all values of $x$ for which each expression is defined, let $A=\cos x\tan x$ and $B=\frac{\sin x}{\tan x}$.
   Show that $A^2+B^2=1$.2 marks
3. The angle $\theta$ is acute and satisfies $\sin\theta=2\cos\theta$.
   Find the exact value of $\cos\theta$.3 marks