A-Level Maths Edexcel (9MA0)

Understand and use

• $\tan{θ} = \dfrac{\sin{θ}}{\cos{θ}}$
• $\sin^2{θ} + \cos^2{θ} = 1$
• $\sec^2{θ} = 1 + \tan^2{θ}$ and
• $\cosec^2{θ} = 1 + \cot^2{θ}$

These identities may be used to solve trigonometric equations and angles may be in degrees or radians. They may also be used to prove further identities.