cos2θ=根号2/3,则sin^4θ+cos^4θ=

cos2θ=根号2/3,则sin^4θ+cos^4θ= 1.已知cos2θ=根号2/3,则sin^4+cos^4的值为________. 已知sinθ=(2/3)根号2,cos2θ=? 已知sinθ/2+cosθ/2=2根号3/5,则sinθ= ,cos2θ=急,谢谢 sin(π/4+θ)*sin(π/4-θ)=2/5,则cos2θ= 若cos2θ=√2/3,则sinθ^4+cos^4的值为 若sinθ=4/5,则cos2θ= 已知sin(π+θ)=-1/3则COS2θ 2sinθ+cosθ/sinθ-3cosθ=-5,求cos2θ+4sinθ 若sin(∏／2）,θ=3／5,则cos2θ=?错了，是sin（∏／2+θ）=3／5,则cos2θ=？ （cos2α）/sin（α-π/4）=-根号下2/2,则cosα+sinα的值 cos2α/sin(α-π/4)=-根号2/2,则cosα+sinπα等于什么 已知cos2θ=根号2/3,则 sin^4θ+cos^4θ的值为________.已经求到（sin^2θ+cos^2θ）^2=1（sin^2θ+cos^2θ）^2-2sin^2θcos^2θ=1-2sin^2θcos^2θ cos2α/[sin(α-π/4)]=-根号2 /2,cosα+sinα=? 若cos2θ=-3/4,则sin^4θ+cos^4θ= 已知sinθ=3/5,θ∈(π/2,π),则cos2θ的值 sin（2π/3+θ）=3/5,则cos2θ=? 若sin(π/2+θ）=3/5,则cos2θ=?