How do you find the antiderivative of secx / (1+tan^2x)secx1+tan2x?

1 Answer
Apr 13, 2015

Maybe with this kind of notation you will realize this integral is very simple :int(sec(x))/(1+tan^2(x))dx = 1/cos(x)*1/(1+tan^2(x))dxsec(x)1+tan2(x)dx=1cos(x)11+tan2(x)dx

(1+tan^2(x))^(-1)=cos^2(x)(1+tan2(x))1=cos2(x)

Then int cos(x) dxcos(x)dx

= [sin(x)]+C=[sin(x)]+C