# Homework Help: How do you solve the double integral

1. Aug 11, 2008

### fk378

1. The problem statement, all variables and given/known data
How do you solve the double integral of cos(u/v) dudv, if the limits of u are v and -v, and the limits of v are 1 and 2?

I tried doing it by parts but I didn't get it...

2. Aug 11, 2008

### rootX

Re: Integral

int {v = 1 to 2}{u=-v to v} cos(u/v) du.dv

treat v as constant and integrate cos, put the limits in (get something like sin(1) ) ..

I did really quickly and had something like 3 sin(1)

P.S. are you using glyn james .. ?

3. Aug 11, 2008

### fk378

Re: Integral

If I integrate cos first and treat v as a constant, then I get v(sin(u/v))...isn't that messy? Can you show me what you did or explain it further please?

And I am using Stewart's calc, not glyn

4. Aug 11, 2008

### rootX

Re: Integral

it goes from -v to v

so

v (sin(v/v)-sin(-v/v))