How to integrate the following ??

intdx/(1 - x^2)^(3/2)dx(1x2)32

1 Answer
Oct 1, 2017

The answer is =x/sqrt(1-x^2)+C=x1x2+C

Explanation:

We need intsec^2x dx=tanxsec2xdx=tanx

We perform this integral by substitution

Let x=sinthetax=sinθ, =>, dx=costheta d thetadx=cosθdθ

1-x^2=1-sin^2theta=cos^2theta1x2=1sin2θ=cos2θ

tan theta=sintheta/cos theta=x/sqrt(1-x^2)tanθ=sinθcosθ=x1x2

Therefore,

int(dx)/(1-x^2)^(3/2)=int(costhetad theta)/(cos^2)^(3/2)dx(1x2)32=cosθdθ(cos2)32

=int(d theta)/(cos^2theta)=dθcos2θ

=intsec^2theta d theta=sec2θdθ

=tantheta=tanθ

=x/sqrt(1-x^2)+C=x1x2+C