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?

Thanks!

-Dan