Thread: Need help integrating

Hi all,

I need help integrating:

intg ((e^t)*cos(n*t))dt

I have tried integrating by parts but it seemed like it just got more complicated. I know there is a theroem but i am not allowed to use it.

Thanks in advance,
ArTiCk

You actually integrate by parts twice and end up with a multiple of

intg ((e^t)*cos(n*t))dt on both sides.

Combine these ans solve

In both cases let u = e^t to get started.

Let me know if it works out

Originally Posted by ArTiCK

Hi all,

I need help integrating:

intg ((e^t)*cos(n*t))dt

I have tried integrating by parts but it seemed like it just got more complicated. I know there is a theroem but i am not allowed to use it.

Thanks in advance,
ArTiCk

CB

Heckuva lot easier than my approach