# A double integral problem

1. Oct 30, 2013

### jaydnul

The problem statement, all variables and given/known data
$$∫∫x^4ydxdy$$
x [-5,10]
y [-1,1]
(don't know how to do a definite integral in the math code...)

$A)10^5$
$B)0$
$C)-10^{10}$

The attempt at a solution
$\frac{x^5y}{5}$ evaluated at -5 to 10.

then
$∫20625ydy$ evaluated at -1 to 1.

My final answer is 20625. What did I do wrong?

2. Oct 30, 2013

### Staff: Mentor

Your integral above is OK, but you fouled up when you evaluated the integrand. Try again.

3. Oct 30, 2013

### jaydnul

I see. 0. thanks

4. Oct 30, 2013

### iRaid

Just fyi, to do a definite integral it's \int_{#}^{#} the _{#} being the bottom number, ^{#} being the top number.

5. Oct 30, 2013

### Staff: Mentor

So the full integral would look like this:
Code (Text):
$$\int_{-1}^1 \int_{-5}^{10} x^4 y dx~dy$$
I put this inside HTML code tags so that you could see the script without the browser rendering it. In rendered form, it looks like this:
$$\int_{-1}^1 \int_{-5}^{10} x^4 y dx~dy$$

6. Oct 30, 2013

### jaydnul

Oh ok good to know. Thanks guys!