若cos2θ=-3⼀4,则sin^4θ+cos^4θ=

2025-01-05 03:51:34
推荐回答(1个)
回答1:

cos2θ=2(cosθ)^2-1=-3/4
(cosθ)^2=1/8 (sinθ)^2=7/8

sin^4θ+cos^4θ=(7/8)^2+(1/8)^2=25/32

请采纳,欢迎追问~