# Math Help - Trig substitution

1. ## Trig substitution

$\int \frac{x}{\sqrt{3-x^4}}dx$

$\int \frac{x}{\sqrt{\sqrt{3}^2-(x^2)^2}}dx$

$x = \sqrt{3}sinx$

$dx = \sqrt{3}cosx$

$\sqrt{3-(3sin^2\theta)^2}$

$\sqrt{3-(1 - 3sin^4\theta)}$

This is where i get stuck.

Any help is appreciated

2. Originally Posted by silencecloak
$\int \frac{x}{\sqrt{3-x^4}}dx$

[snip]
If you make the substitution $u = x^2$ you get a standard form ....

3. doh

i need to develop an eye for these sorts of things still

thanks