# Math Help - Integral Error

1. ## [Solved] Integral Error

The integral <cos(mx),cos(mx)> is supposed to equal 1 but I am not obtaining the result.

Can someone see what is going wrong?

It is the 2nd integral in the pdf.

2. The problem is solved. In case you want to know, m and n have to be assumed to be integers; thus, making sin 0.