y2(1−sin2x)y_{2}(1-\sin 2 x)y2(1−sin2x)
(1−sin2x)(1-\sin 2 x)(1−sin2x)
1/2(1−cos2x)1 / 2(1-\cos 2 x)1/2(1−cos2x)
1/2(1−tan2x)1 / 2(1-\tan 2 x)1/2(1−tan2x)
(1−cos2x)(1-\cos 2 x)(1−cos2x)