化简 1.sin(α-2π)sin(α+π)-2cos(α-π/2)sin(α-π)-cos²(π/2+α)sin²(α-π/2)2.————————————cos(α-3π)sin(3π/2+α)第二个是 cos(α-3π)sin(3π/2+α)分之 sin²(α-π/2)
化简sin(α+β)+sin(α-β)+2sinαsin(3π/2-β)=
化简sin^2(α-π/6)+sin^2(α+π/6)-sin^2α
化简sin^2α+sin^2β+2sinαsinβcos(α+β)
化简sin(α+β)-2sinαsinβ/2sinαsinβ+cos(α+β)
1.证明 cos(α-π/2)=sinα sin(α-π/2)=﹣sinαcos(α-π/2)=sinαsin(α-π/2)=﹣sinα
化简sin(-π/2-α)sin(πα)cos(-α-π)/cos(π-α)sin(3π α)
化简 {sin(π+α)cos(α-2π)tan9π/4}/sin(-α)sin(7π/2+α)过程
化简1-sin[α-2π]sin[π+α]-2sin²[-α].
化简sin²α-2sinαcosα+1
化简:sin(2π-α)cos(π+α)cos(11π/2-α)/cos(π-α)sin(3π-α)sin(-π-α)sin(9π/2+α)
化简sin(30+α)-sin(30-α)
2sin(α+π/3)=sinα+______
为什么sin(2π-α)=-sinα?
sin(kπ+α)化简
化简:(sinα-cosα)^2+sin4α/2cos2α 化简:sin^2x+sin^2(x+2π/3)+sin^2(x-2π/3)
化简 sin(π+α)+sin(2π+α)+sin(3π+α)+……+sin(kπ+α) k属于Z
sin(α+β)-2sinαcosβ/2sinαsinβ+cos(α+β)化简
化简:sin(α+β)-2sinαcosβ/2sinαsinβ+cos(α+β)