## anonymous 4 years ago Can anyone please explain how to use Double and Half Angle formulas to find exact values?

1. anonymous

of what?

2. anonymous

in trigonometry !

3. anonymous

of any given number both on and off the Unit Circle. For example if I needed to find the a) sin(2x) b) cos(2x) c) sin(x/2) and d) (cos x/2) if the cos(x)=(3/5), 0<x<(π/2)

4. anonymous

$\sin (2x)=2\sin x.\cos x$ $\cos (2x)=\cos ^{2}x -\sin ^{2}x$ in which the angle 2x is divided by 2 .. if it was x/2 << divide it bye 2 to be x/4 |dw:1327542672309:dw|

5. anonymous

|dw:1327542889414:dw|