How do you evaluate the integral int dx/(x^2sqrt(x^2-3))?

1 Answer
Aug 31, 2017

After using x=sqrt(3)*secu and dx=sqrt(3)*secu*tanu*du transforms, this integral became,

int (sqrt(3)*secu*tanu*(du))/[3(secu)^2*sqrt(3)*tanu]

=1/3*int (du)/secu

=1/3*int cosu*du

=1/3*sinu+C

After using x=sqrt(3)*secu, secu=x/sqrt(3), tanu=sqrt(x^2-3)/sqrt(3) and sinu=tanu/secu=sqrt(x^2-3)/x inverse transforms, I found,

int (dx)/[x^2*sqrt(x^2-3)]=sqrt(x^2-3)/(3x)+C

Explanation:

I used x=sqrt(3)*secu and dx=sqrt(3)*secu*tanu*du transform