One more trig identity please

http://latex.codecogs.com/gif.latex?...plus;&space;1}

Thank you

What have you done? Do you know identities for cos(2x) and sin(2x)?

Am I somewhat close?
http://latex.codecogs.com/gif.latex?...ce;+cosx}

multiply that by (cos x+sin x)/(cos x+sin x)

Edit: oh, you were done two steps before. Expand the denominator.