# Thread: [SOLVED] What integration technique to use?

1. ## [SOLVED] What integration technique to use?

Substitution, trig, or partial fractions do not work.
I have tried integration by parts and all it does is give me either a cos(3x) or back to a sin(3x).
Here is the problem...
Integrate (e^(2x))sin(3x) dx

I can't think of another way around it.

2. look at post #3 in this thread to see the idea for the integral

It is integration by parts twice

http://www.mathhelpforum.com/math-he...ion-parts.html

3. You integrate this by parts twice.
It doesn't matter which you use as u or dv.
Just make the same substitution the second time.
What happens is, you get back to the same integral,
BUT with a different coefficient.
Move that over to the left side and solve for the integral
and do NOT forget the +C.

4. Hey thanks guys! I don't know why I did not see that...even though I worked through the whole thing like twice!