# Math Help - More Calculus

1. ## More Calculus

I've gotten as far as the line before the last, but I'm not sure whether the last line has integrated by parts (yet again - third time) the integral, or what it has assumed?

2. The last line simply recognises that $\int e^{x} cos(mx)$ is I, the thing you tried to integrate in the first place.

Then it factorises.

3. Originally Posted by maggiec

I've gotten as far as the line before the last, but I'm not sure whether the last line has integrated by parts (yet again - third time) the integral, or what it has assumed?

Dear maggiec,

In addition to what SpringFan25 said it also assumes that m is an integer.

4. Originally Posted by SpringFan25
The last line simply recognises that $\int e^{x} cos(mx)$ is I, the thing you tried to integrate in the first place.

Then it factorises.
Thank you! I can't believe I didn't see that!