Tell me more ×
Mathematics Stack Exchange is a question and answer site for people studying math at any level and professionals in related fields. It's 100% free, no registration required.
up vote 0 down vote favorite

If a double integration gives a minus result as the answer, what does it mean? What is minus volume?

share|improve this question
If it is supposed to represent volume, take the absolute value of your answer (provided your limits are correct but you interchanged the top surface and the bottom surface). If it is an arbitrary integral then there is nothing wrong, again provided you computed the double integral correctly. – glebovg Nov 10 '12 at 4:16
1  
Ordinarily, a negative result in a volume calculation is a strong indication that there has been a mistake. – André Nicolas Nov 10 '12 at 4:18
the inner integral is respect to y and the outer integral is respect to x. the upper x limit is 2 and the lower limit is 0. the upper y limit is x and the lower limit is x to the power two. This was an example in a pdf tutorial. – Fazlan Nov 10 '12 at 4:23
if we draw the x,y region, the region breaks into two pieces. So aren't we supposed to integrate both the regions seporately? – Fazlan Nov 10 '12 at 4:30
2  
I wrote that before getting the URL. The calculation seems fine, it is jut the evaluation of a specific double integral. Not all double integrals can be interpreted as volumes. Because of your reference to volume in the OP, I thought you were asked to find a particular volume. – André Nicolas Nov 10 '12 at 5:24
show 4 more comments

Know someone who can answer? Share a link to this question via email, Google+, Twitter, or Facebook.

Your Answer

 
discard

By posting your answer, you agree to the privacy policy and terms of service.

Browse other questions tagged or ask your own question.