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: where θ is ...

Solve trigonometric equations in Higher Maths using the double angle formulae, wave function, addition formulae and trig identities.

Using the double angle formulae; Equations involving compound angles (extension) ... Let's remind ourselves of what the sine graph looks like so that we can see how many solutions we should be ...