已知sin( π/2+ θ )=3/5则cos( π -2 θ )等于

已知sin(3π-α)=-2sin(π/2+α)则sinαcosα 求值:已知sinθ+cosθ=1/5,已知θ∈(0,π).求(1)sinθ*cosθ(2)sinθ-cosθ(3)tanθ 已知sinθsinβ=-4/7,则cosθcosβ∈已知tan(π-θ)=3,求下式的值 (5xin^3θ+cosθ)/(2cos^3θ+sin^2θcosθ) 已知sinθ=3/5,θ∈(π/2,π),则cos2θ的值 已知sin( π/2+ θ )=3/5则cos( π -2 θ )等于 已知sin(x+π/6)=1/3,求sin(5π/6-x)+sin^2(π/3-x) 已知sin(x+π/6)=1/4,求sin(5π/6-x)+sin^2(π/3-x) 已知tanθ=3,求(3cosθ-5sin^2θcosθ)/sin(π-θ)的值 已知θ为第三象限角,1-sinθcosθ-3cos^2=0则5sin^2θ+3sinθcosθ=? 1.已知2sin(3π+θ）=cos(π+θ）,求2sin 已知α∈(π/2,π),sin(-α-π)=根号5/5,则sin(α-3/2π)= 已知sinθ-cosθ=1/3,则sin^2θ的值为 已知sinα=3/5且α属于(π/2,π),则sin(α+π/3)= 已知sin(π/2+a)=3/5,a∈(0,π/2),则sin(π+a)= 已知sin(π-α)+sin(5π/2+α)=根号2/3(π/2 已知sin(π/6-a)=根号3/3,则sin(5π/6+a)= 已知sin(3π-a)=-2sin(π/2+a)则sinacosa等于 已知sin(α+π/3)+sinα=-4√3/5(-π/2