# Math Help - Integral1

1. ## Integral1

Calculate:

$\int \frac{xdx}{\sqrt{x^4-2}}$

2. Originally Posted by Apprentice123
Calculate:

$\int \frac{xdx}{\sqrt{x^4-2}}$
first do a substitution of $u = x^2$ to obtain $\frac 12 \int \frac 1{\sqrt{u^2 - 2}}~du$

now do a trig substitution: $u = \sqrt{2} \sec \theta$

3. thanks