How do you integrate int sinxln(cosx) by integration by parts method?

1 Answer
Aug 11, 2016

-cos(x)loge(cos(x))+cos(x) + C

Explanation:

d/(dx)(cos(x)log_e(cos(x)))=-sin(x) log_e(cos(x))-sin(x)

so

int sin(x) log_e(cos(x))dx =
= -int d/(dx)(cos(x)log_e(cos(x)))dx-int sin(x) dx =
= -cos(x)loge(cos(x))+cos(x) + C