What is the Integral of tan^2 x sec^4 x dx?

1 Answer
May 27, 2018

I=tan^3x/3+tan^5x/5+c

Explanation:

We know that,

(1)color(red)(int[f(x)]^nd/(dx)(f(x))dx=[f(x)]^(n+1)/(n+1)+c, where,(n!=-1,f(x)>0 and f'(x)!=0)

We have,

I=inttan^2xsec^4xdx

=int tan^2x(sec^2x)sec^2xdx

=inttan^2x(1+tan^2x)sec^2xdx

=int tan^2xsec^2xdx+inttan^4xsec^2xdx

=int(tanx)^2d/(dx)(tanx)dx+int(tanx)^4d/(dx)(tanx)dx

=(tanx)^3/3+(tanx)^5/5+c...to Apply(1)

=tan^3x/3+tan^5x/5+c