sin(π/6+α)=3/5,则cos(α-π/3)=
已知sin(3π−α)=−2sin(π2+α),则sinαcosα=( )
已知(3sinα+cosα)/(3cosα-sinα)=2,则2-3sin(α-3π)sin(1.5π-α)-[cos(
若sinα+cosαsinα−cosα=2,则sin(α-5π)•sin(3π2-α)等于( )
若(sinα+cosα)/(sinα-cosα)=2 则sin(α-5π)·sin(3π/2-α)=?
已知cos(α-π/6)+sinα=4√3/5,则sin(α+7π/6)的值是
已知cos(α-π/6)+sinα=4/5 根号3,则sin(α+7/6π)=?
用向量法证明cos(α-β)=cosαcosβ+sinαsinβ
求证sin^2α+cosαcos(π/3+α)-sin^(π/6-α)的值与α无关
sin^2(α)+cosαcos(π/3+α)-sin^2(π/6-α)为定值,要证明
已知sin(α-π/4)=1/3,则cos(π/4+α)的值等于
已知α为锐角,且cos(α+π/4)=3/5,则sinα=
已知α为锐角,且cos(α+π/4)=3/5,则sinα=?