Take the 2-minute tour ×
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.

Let $f(x,y) = xy$ on the square $[0, \pi]^2$. Find the Fourier cosine-cosine series of $f$.

I am working on this question with a group and one of us gets all the coefficients as zero. Is this correct or not?

Also, we are at a disagreement about whether to integrate over $[-\pi,\pi]$ or $[-\pi /2,\pi /2]$.

share|improve this question
then?.......... –  Xiaolang Apr 12 '13 at 2:40
Sorry I forgot a part of it –  Username Unknown Apr 12 '13 at 2:41
Your title doesn't match your definition of $f$. –  Stefan Smith Apr 12 '13 at 3:40
Could you briefly recall how the Fourier cosine-cosine series is defined? –  1015 Apr 12 '13 at 3:46
I am unsure what you are asking because it is a long summation that consist of sines and cosines and sine-cosine and cosine-sine and cosine-cosine and sine-sine. –  Username Unknown Apr 12 '13 at 3:50

Your Answer


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

Browse other questions tagged or ask your own question.