Thread: integration by parts

can some make sense of this, where does the 5/4 I come from? i know you have to do some shifting because the last integral is "e^(-theta)cos2(theta)d(theta)" which is the same as the intial one.

thanks

Yes, your initial integral is called I. By using integration by parts the same integral came back in the righthandside of the equation. So you can now solve the equation for I, your initial integral. That's basically all.

oh.. so I move 1/4 over to the left side and solve for I?? i get it. thank u!