化简 1+sin(α-2π)·sin(π+α)-2cos平方(-α)要有过程

化简sin(α+β)+sin(α-β)+2sinαsin(3π/2-β)= 化简 1+sin(α-2π)·sin(π+α)-2cos平方(-α)要有过程 化简1－sin[α－2π]sin[π＋α]－2sin²[－α]. 化简sin^2(α-π/6)+sin^2(α+π/6)-sin^2α sin(π-α)=-2sin(π/2+α),求sinα·cosα 化简 1+sin(α-2π)*sin(π+α)-2cos^2(-α) 1+sin(α-2π)*sin(π+α)-2cos^2(-α) 化简 化简1+sin(α-2π)sin(π+α)-2cos^2(-α), 化简：2cos²α-1/【2sin(π/4-α)sin²(π/4+α)】 化简：2cos²α-1/【2sin(π/4-α)sin²(π/4+α)】 化简1+sin(α-2π)sin(π+α)-2cos(-α) 化简,①sin（-1071°）×sin99°+sin（-171°）×sin（261°）②1+sin（α-2π）×sin（π+α）-2cos2（-α） 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: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(-a)cos(2π+a)sin(-a-π) sin(π/4+α)sin(π/4-α)=1/4 求2sin^2(a) -1+tana-1/tan sin(kπ+α)化简