∫[(sinxdx)/(cos^2x + cos x -2)]

what i did was integration by parts but it is wrong.....and i couldn't even finish it

=∫sinxdx/(cosx-1)(cosx+2)

sinx/cos^2+cosx-2 = A/cosx-1 + B/cosx +2

sinx = Acosx + 2A + Bcosx -B

sinx = cosx(A+B) + (2A-B)

2A-B=0