Double angle formulas are named so because they involve trigonometric functions of double angles, i.e., sin2θ, cos2θ and tan2θ. There are three main double angle formulas as below: ...

Learn and revise trigonometric ratios of sine, cosine and tangent and calculate angles and lengths in right-angled triangles with GCSE Bitesize AQA Maths.

Revise trigonometric ratios of sine, cosine and tangent and calculate angles in right-angled triangles with this Bitesize GCSE Maths Edexcel guide.