sin2/3π=sin(π-π/3)吗?
sin2/3π=sin(π-π/3)吗?
sin(α+π/4)=1/3,则sin2α
若sin(π/4+α)=sinθ+cosθ,2sin^2β=sin2θ,求证:sin2θ+2cos2β=3
证明:sinπ/9[(sinπ/9)+sin(3π/9)]=sin2(2π/9)
sin2(π3
设sin(π/4+θ)=1/3,则sin2θ=
已知sin(θ+π/4)=1/3,求sin2θ
已知α∈(0,π/2),且2sinα-sinαcosα-3cosα=0.求[sin(α+π/4)]/[sin2α+cos
已知α,β均为锐角,且满足3sin^2α+2sin^2β=1,3sin2α-2sin2β=0 求证:α+2β=π/2
已知α∈(π/4,π/2)若sin2α=3/5则sinα-cosα=
已知sinα=1/3,α∈(π/2,π),求sin2α,cos2α,tan2α的值
已知sinα=3/5,α∈(π/2,π),求sin2α,cos2α的值