sin(5π+π/2+α)

计算,sin(π/12)-sin(5π/12)+2sin(π/8)sin(3π/8) 化简sin(α+β)+sin(α-β)+2sinαsin(3π/2-β)= sin(5π+π/2+α) sinα=4/5,π/2 若（sinα+cosα）/（sinα-cosα）=2 则sin(α-5π)·sin(3π/2-α)=? 若sinα+cosα/sinα-cosα=2,则sin(α-5π）*sin（3π/2-α）等于? 若(sinα+cosα)/(sinα-cosα)=2,求sin(α-5π)sin(3π/2-α)的值 2sin(α+π/3）=sinα+______ 为什么sin(2π-α)=-sinα? sin(π-α)=-2sin(π/2+α),则sinαcosα等于 sin(π-α)=-2sin(π/2+α),求sinα·cosα 已知sin(3π-α)=-2sin(π/2+α)则sinαcosα 化简sin^2(α-π/6)+sin^2(α+π/6)-sin^2α 求sin^2α+sin^2(π/3 +α)+sin^2(π/3 -α) 求值sin^2(α-π/6)+sin^2(α+π/6)-sin^2α Sin（5π+α)=sin(π+α)=-sinα正确吗? sin(α+π/6)=-4/5,α属于（-π/2,π/2),求sinα 若α∈(π/2,π),sin(α+π/6)=3/5,sinα=