What is int x/(1+sinx) dx?

1 Answer
Mar 9, 2018

x(tanx-secx)+ln|(secx+tanx)/secx|+c

Explanation:

I=intx/(1+sinx)dx=int(x(1-sinx))/(1-sin^2x)dx=int(x(1-sinx))/cos^2xdx
=>I=intxsec^2xdx-intxsecxtanxdx
Integration by parts,we get
I=[xtanx-int1*tanxdx]-[x*secx-int1*secxdx]
I=xtanx-ln|secx|-xsecx+ln|secx+tanx|+c
=xtanx-xsecx+ln|secx+tanx|-ln|secx|+c
=x(tanx-secx)+ln|(secx+tanx)/secx|+c