11/19/2009, 01:07 AM

(11/18/2009, 04:46 PM)tommy1729 Wrote: contour of what ? of the function we are defining with the contour ?

The gradient theorem and residue theorem both show that in many cases the value of a contour integral/line integral is independent of the contour of integration.

So the simple answer to your question is: in many cases, it doesn't matter what the contour of integration is, you get the same result.