Question

Another integral

Answer 1

\[\int\limits_{\sqrt{2}}^{2} \frac{ 1 }{ x^3\sqrt{x^2-1} }dx\]

Answer 2

i think the sub would be x=sec(theta)

Answer 3

1-sin^2(theta)=cos^2(theta)
sin^2(theta)-1 is not cos^2(theta)