## anonymous 5 years ago $\int\limits_{}^{}(\cos x- \cos 2x) dx/1-cosx$

1. anonymous

$=\int\limits_{}^{}((\cos x-1)+(1-\cos 2x))dx/(1-\cos x)$ $=\int\limits_{}^{}dx+\int\limits_{}^{}2\sin ^{2}xdx/(1-\cos x)$ $x+\int\limits_{}^{}2\sin ^{2}xdx/(2\sin ^{2}x/2)$ $x+\int\limits_{}^{}4\cos ^{2}x/2dx$i think now you can do the simple integration

2. anonymous

it should be -x and how did you get this?? $\int\limits\limits_{}^{}4\cos ^{2}x/2dx$

3. anonymous

yes it should be -x. sin x=2sin(x/2)cos(x/2). use this in the gration.