more integrals

[jeca86]

evaluate the integral.

the integral of e^-theta * cos2theta * dtheta

i have:

u=cos2theta,
du=-2sin2*dtheta

dv-e^-theta
v=-e^-theta

=-e^-theta * cos2theta - integral of e^-theta * 2sin2*dtheta
is this right? this is where i get stuck.

 

[Unco]

Nice work.

Now if you do parts on \(\displaystyle \mbox{-2\int e^{-\theta}\sin{(2\theta)} d\theta}\) what do you notice?

 

[jeca86]

oh wow thanks