Help with double integral problems

1. Aug 3, 2012

elvishatcher

Can someone explain to me how I would arrive at this answer?:
http://www.wolframalpha.com/input/?...m+x=y+to+x=sqrt(pi/2)+and+y=0+to+y=sqrt(pi/2)

This double integral problem came up in a practice test I was taking, and I just can't figure it out. I tried integrating it but couldn't figure out how to integrate cos(x^2)dx and when I put that into Wolfram Alpha it said it involved some special function that seems much too advanced for the level of the course the test is from (it's from a first year multivariable calculus class). Thanks!

2. Aug 3, 2012

LCKurtz

Draw the region then use your picture to reverse the order of integration.

3. Aug 3, 2012

elvishatcher

Aha, got it. Thanks much.