Strategy for Further Trigonometric Equations (AQA A-Level Mathematics): Quizzes

Multiple angles and double-angle identities

$2\sin \theta \cos \theta$

$2\cos^2 \theta - 1$

$\frac{1}{2}[\cos(A-B) - \cos(A+B)]$

$\theta = \theta_0 + 180^\circ n$

Substitution (e.g., $u = \sin \theta$)

When squaring both sides of an equation

$\sqrt{a^2 + b^2}$

$\frac{b}{a}$

$\sin A \cos B + \cos A \sin B$