Indefinite integral of $\cos^{3}(x) \cdot \ln(\sin(x))$ I need help. I have to integrate $\cos^{3} \cdot \ln(\sin(x))$ and I don´t know how to solve it.  In our book it is that we have to solve using the substitution method. If somebody knows it, you will help me..please 

Substitute :
$\sin x =t \Rightarrow \cos x dx =dt$ , hence :
$I=\int (1-t^2)\cdot \ln (t) \,dt$
This integral you can solve using integration by parts method .
