Trigonometric Proof (Edexcel A-Level Mathematics): Quizzes

All values within the domain

The more complex side

$1 + \tan^2 \theta = \sec^2 \theta$

$\sec \theta = \frac{1}{\cos \theta}$

$\tan \theta = \frac{\sin \theta}{\cos \theta}$

$\sin 2\theta = 2\sin \theta \cos \theta$

$\csc^2 \theta = 1 + \cot^2 \theta$

Converting to sine and cosine

LHS = RHS

$\sec^2 \theta = 1 + \tan^2 \theta$