Hi,
I'm asked to integrate e^2xcosxdx. I have used intefration by parts letting u=e^2x and dv=cosxdx. This results in
e^2xsinx-the integral of 2sinxe^2x. I then integrated by parts again and the overall result was if I = integral of e^2xcosxdx then
I= e^2xsinxdx-e^2xsinxdx + 0.5( I)
0.5I = 0
Therefore I=0
Is this wrong?
You should end up with the same integration but with a minus sign on the right side. You move that integration to the left hand side and then divide by two.
So you should end up with something like:
I= .......... -I (move right hand integration to left hand side)
2I = .............. (divide by two)
I = 1/2(..........) (Final answer)
Sorry i didn't do the integration. In class right now =p