Verifying Identities

[lewch45]

Can someone please help with the following identities???

(1) sin ^2 (x/2) + cos x = cos ^2 (x/2)

(2) (2 cos 2x/ sin 2x) = cot x - tan x

Any help would be greatly appreciated!!!!

 

[royhaas]

(1) Write $\displaystyle cos(x)$ as a function of $\displaystyle sin(x/2)$.
(2) Use the formula for $\displaystyle tan(2x)$ as a function of $\displaystyle tan(x)$.