∫sinx+cosx√sin2xdx
Put sinx−cosx=t
(sinx+cosx)dx=dt
t2=1−sin2x
⇒sin2x=1−t2
=∫dt√1−t2
=sin−1t+c
=sin−1(sinx−cosx)
=sin−1(√2sin(x−π4))tc