# Homework Help: Problem sheet double integration

1. Jan 19, 2010

### the_godfather

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

$$\int\int x^3(x^2+y^2)$$ dy dx limts of x between 2 and -4 and y limits between 5 and 0

2. Relevant equations

3. The attempt at a solution

i get an answer -17426 2/3 which doesn't seem right

plugged the formula into maple and has given me an answer of -5860.

my first step was to expand the brackets.

to get $$\int\int x^5 + x^3y^2$$ then integrate with respect to dy. put the limits of y in as 5 and 0.

$$\int 5x^5 + (125x^3/3)$$
then integrate with respect to x and again put the limits in.

2. Jan 19, 2010

### Dick

I agree with Maple. I also agree with your x integration. Except I would put a minus sign in front because I integrated with a lower y limit of 5 and an upper y limit of 0. Is that what you meant? You'll have to show more intermediate results to be able to tell what you are doing wrong.