I tried to solve this integral but i was not able to get an answer. I tried foiling the integrand and go from there but was not able to succeed.
Find integral
integral from 0 to pi (xsinx+cosx)(xcosx+sinx)dx
THey gave me a hint
Hint: sinxcosx= 1/2sin2x
So far i just foiled and got the following for the integrand:
x^2sinxcosx + xsin^2x+ xcos^2x + cosxsinx dx
oh ok it makes so much sense. Now, when I substitute 1/2 sin2x into x^2sinxcosx I don't get x^2sin2x...I get x^2 times 1/2 sin2x
what is wrong with it? i cant see my mistake
ok i think i got it. I took out the constant 1/2 and then integration by parts for x^2sin2x