This is going to end up being a simple question with a simple answer, but I just can't tweak the answer out of my Math Methods text.
I have the following statement:
( and are real 3-vectors and is the usual dot product.)
I'm supposed to get that
But looking at the integral I'm thinking it ought to be:
which would give me 0, which obviously isn't true. So (sigh) what am I doing wrong?