# Homework Help: Integral of cos(8x^2)? multivariable calc

1. Feb 23, 2012

### omonoid

Integral of cos(8x^2)??? multivariable calc

1. The problem statement, all variables and given/known data

2. Relevant equations

none

3. The attempt at a solution

So i reversed the order...

and couldn't figure out how to integrate cos(8x^2). I looked at my trig identities, tried on my graphing calc, and even wolfram alpha gave me a strange answer that i cant use.

Either i'm doing something wrong, or missing something obvious.

Thanks
Jake

2. Feb 23, 2012

### alanlu

Re: Integral of cos(8x^2)??? multivariable calc

...dy dx?

3. Feb 23, 2012

### omonoid

Re: Integral of cos(8x^2)??? multivariable calc

oh yeah. in my work i should have wrote dydx instead of dxdy good catch. wow. maybe i can solve it now.

lets see...

wow... the answer was 0, after a page of work and a few hours of confusion

Last edited: Feb 23, 2012