若sin2α=1/4,π/4
若sin2α=1/4,π/4
sin(α+π/4)=1/3,则sin2α
sin2α+sin2β-sin2αsin2β+cos2αcos2β=1 证明
已知sin2α=3/5(-3π/4
若sin(π/4+α)=sinθ+cosθ,2sin^2β=sin2θ,求证:sin2θ+2cos2β=3
sin(π/4+α)sin(π/4-α)=1/6 求sin2α
若2sin(π/4+θ)=sinθ+cosθ,2sin^2(β)=sin2θ,求证sin2α+1/2cos2β=0
sin(π/4+α)=1/4,则sin2α=?
已知2sin^α+sin2α/1+tanα=k(π/4
已知(2sin^2α+sin2α)/(1+tanα)=k,(π/4
已知sin2α=1/3,则cos²(α-π/4)=
已知sin2α=1/3,则cos²(α-π/4)= 只要结果