sin（-π/3）+2sin（5π/3)+3sin(2π/3)的值为多少

计算,sin(π/12)-sin(5π/12)+2sin(π/8)sin(3π/8) 2sin(α+π/3）=sinα+______ 化简sin(α+β)+sin(α-β)+2sinαsin(3π/2-β)= sin（-π/3）+2sin（5π/3)+3sin(2π/3)的值为多少 sin（-19π/6）=?已知[3Sin(π+a)+Cos(π-a)]/4Sin(-a)-Sin(5π/2+a)=2，求tan a 若（sinθ+cosθ）/（sinθ-cosθ）=2,则sin（θ-5π）*sin（3π/2-θ）等于? 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? 化简 sin(5π/2-a) 和 sin（a-3π/2）RT 已知sinα=4/5,求下列三角函数值1）sin（-α）2）sin（π-α）3）sin（π+α）4）sin（2π-α） sin^2(π/3-x)+sin^2(π/6+x) Sin(π+π/6)Sin(2π+π/6)Sin(3π+π/6).Sin(2008π+π/6)求值 sin(-5π/3)等于 2sin π/6 =sin π/3,吗,求解释,还有-sin π/6=sin- π/6吗 [sin(a-6π)cos(7π/2-a)]/[sin(3π+a)+sin(a-π）】= 已知sin(x+π/6)=1/3,求sin(5π/6-x)+sin^2(π/3-x) 已知sin(x+π/6)=1/4,求sin(5π/6-x)+sin^2(π/3-x) 求sin(π/14)*sin(3π/14)*sin(5π/14)的值