# integration help

• Oct 17th 2009, 03:28 PM
messianic
integration help
I need help integrating teh following functioN:

(x^3)(e^(x^2)
• Oct 17th 2009, 03:33 PM
Chris L T521
Quote:

Originally Posted by messianic
I need help integrating teh following functioN:

(x^3)(e^(x^2)

Apply the substitution $u=x^2$ to get $\tfrac{1}{2}\int ue^u\,du$.

Then apply integration by parts.

Can you take it from here?
• Oct 17th 2009, 03:51 PM
messianic
well it is x^3 so the u in the integral should be u^3/2 right? This complicates things. Can you explain further
• Oct 17th 2009, 04:01 PM
mr fantastic
Quote:

Originally Posted by messianic
well it is x^3 so the u in the integral should be u^3/2 right? This complicates things. Can you explain further

Wrong. Have you been taught how to do a 'u-substitution' when integrating?
• Oct 17th 2009, 04:21 PM
messianic
yes but a while ago.