若f (sin x ）＝3－cos 2x 则f (cos x )＝
若f (sin x ）＝3－cos 2x 则f (cos x )＝
日期：2022-03-28 09:30:55 人气：1
f(sinx)=3-cos2x
=3-(1-2sin²x)
=2+2sin²x，
f(cosx)=2+2cos²x
=2+(2cos²x-1)+1
=3+cos2x
=3-(1-2sin²x)
=2+2sin²x，
f(cosx)=2+2cos²x
=2+(2cos²x-1)+1
=3+cos2x