Double integral problem

**weber** · October 2nd 2011, 02:47 PM

Dear MHF users!
I'm having problems with this integral:

because in the first step, i dont know how to integrate this part:

Thanks a lot!

**TheEmptySet** · October 2nd 2011, 03:13 PM

Originally Posted by weber

Dear MHF users!
I'm having problems with this integral:

because in the first step, i dont know how to integrate this part:

Thanks a lot!

I am going to guess that there is a typo in your problem. You state you don't know how to integrage

$\iint xy^{xy^2}\, dy \, dx$

but then you say you don't know how to integrate $e^{x^2y}$

My guess is you mean this integral

$\iint xye^{xy^2}\, dy \, dx$

If that is the case you need to use a substition

$u=e^{xy^2} \implies du=2xye^{xy^2}dy \iff \frac{du}{2}=xye^{xy^2}dy$

Now your integral is

$\frac{1}{2}\iint u \, du \, dx$

**weber** · October 2nd 2011, 03:15 PM

OMG! you are 100% right!
Sorry for my typo =/

That's exactly what i wanted.

TheEmptySet, you are awesome! (:

Thread: Double integral problem

LinkBack

Thread Tools

Display