Double Angle Formulae (Edexcel A-Level Mathematics): Quizzes

$2\sin(\theta)\cos(\theta)$

Three

$\frac{2\tan(\theta)}{1 - \tan^2(\theta)}$

$\frac{24}{25}$

$\frac{-119}{169}$

$22.5°, 112.5°$

$1 - 2\sin^2(\theta)$

From compound angle formulae by setting $A = B$

To avoid losing solutions where $\cos x = 0$

Finding exact values of logarithms