# Evaluating and integral using random numbers

1. Feb 20, 2008

### ToxicBug

1. The problem statement, all variables and given/known data
Hello! I need to evaluate the following integral by using random numbers. I just need help with rewriting the boundaries of the integral to both be [0,1]

2. Relevant equations
$$\iint \frac{\,x_1\,x_2}{\,(1+2x_1)^2\exp(x_2^2)}\,dx_1\,dx_2$$
The integral on the following region:
$$2<x_1<x_2<\infty$$

3. The attempt at a solution
I've no idea how to transform the double integral, but I know that for a single integral I need to use the substitution $$y=e^{-x}$$

2. Feb 20, 2008

### jacobrhcp

well... I'm not really sure so someone should confirm this, but you can write the intergrand as a product f(x1)g(x2) and then you can just put the f(x1) in front of the one integral, and the g(x2) in front of the other. So now you have the product of two single integrals, can you solve those?