Integrate by parts twice help

1. Feb 6, 2004

Klion

I am studying for a midterm, was browsing over an old midterm and found this question

$$\int e^{3x} \cos{(x)}\; dx$$

Can't figure it out, help would be appreciated

2. Feb 6, 2004

jamesrc

Integrate by parts twice. Post back if you get stuck.

3. Feb 6, 2004

Klion

erm didn't think we'd gotten that far, assignment on that section isnt due until monday. No wonder I couldn't find it hehe.

O well I have 2 hrs to learn it I'm good! :)

4. Feb 6, 2004

Klion

hmm I ended up with

$$\int e^{3x} \cos{(x)}\; dx = \frac{e^{3x}\sin{(x)} + 3e^{3x} \cos{(x})} {10}$$