Could somebody check my solution if it is correct.

I got the answer -4.

I don't know if it is right or not.

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- May 16th 2007, 12:52 PMtotalnewbieMultiple integral to check
Could somebody check my solution if it is correct.

I got the answer -4.

I don't know if it is right or not. - May 17th 2007, 12:11 AMCaptainBlack
First observe that the integrand (4-y) is positive on D. Therefore the integral

over D cannot be negative.

The region of integration is 0<x<2, x^2/4<y<1, so our integral may be written:

I = integral_{x=0,2} [integral_{y=x^2/4,1} (4-y) dy] dx

.. = integral_{x=0,2} [7/2 - x^2 + x^4/32] dx

.. = 68/15 = 4.533..

Which agrees with my numerical result using MonteCarlo methods of 4.535.

RonL - May 17th 2007, 06:09 AMtotalnewbie
- May 17th 2007, 06:18 AMCaptainBlack
Trying to sort out time zones can be a problem online, you have yours

set up 3 hours east of me, but your ISP appears to be in the Netherlands!?

But to be brief - When was 10 AM? My post is time stamped 08:11 (AM)

and your reply 14:09 (02:09 PM) in my time zone.

OK repeat search - Estonia!

RonL