Evaluate ∫1−tanx1+tanxdx
logcosx+sinx+C
logcosx-sinx+C
logtanx+sinx+C
None of these
∫1−tanx1+tanxdx=∫cosx−sinxcosx+sinxdx=∫ddx(cosx+sinx)cosx+sinxdx=logcosx+sinx+C