For 1, put sin x - cos x = t. So dt = cos x + sin x
t2 = 1 - sin 2x, so replace sin 2x by 1 - t2
Q1)∫0pi/4 sin x+cos x/9+16sin 2x
Q2)∫0 pi/2 sin2x tan-1(sinx)dx
For 1, put sin x - cos x = t. So dt = cos x + sin x
t2 = 1 - sin 2x, so replace sin 2x by 1 - t2