How do you find the antiderivative of (sinx + cosx)/tanxsinx+cosxtanx?

1 Answer
Jul 27, 2016

sinx+ln|tan(x/2)|+cosx+Csinx+lntan(x2)+cosx+C

Explanation:

I=int(sinx+cosx)/tanxdx=int(sinx+cosx)cosx/sinxdxI=sinx+cosxtanxdx=(sinx+cosx)cosxsinxdx

=intcosxdx+intcos^2x/sinxdx=sinx+int(1-sin^2x)/sinxdx=cosxdx+cos2xsinxdx=sinx+1sin2xsinxdx

=sinx+int{1/sinx-sinx}dx=sinx+{1sinxsinx}dx

=sinx+int(cscx-sinx)dx=sinx+(cscxsinx)dx

:. I=sinx+ln|tan(x/2)|+cosx+C