已知sin(α+π/3)=√2/4,π/6＜α＜2π/3,则cos(2π/3 + α)=?

已知sin(α+π/3)+sinα=-4√3/5(-π/2 已知sin(3π-α)=-2sin(π/2+α)则sinαcosα 已知sinα=﹣4/5,求√2 sin(α+π/4)的值 已知sin(π/4+α)=√3/2,则sin(3π/4-α)值为 已知sin(α+π/4)=3/5,π/2 已知sin(45度-α)=-2/3,π/4 已知sin(x+π/6)=1/4,求sin(5π/6-x)+sin^2(π/3-x) 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） 已知-π/6＜=β＜π/4,3sin^2α-2sin^2β=2sinα,求sin^2β-1/2sin^2α的最值. 已知β∈[-π/6,π/4）,且3（sinα）^2-2（sinβ）^2=2sinα,求（sinβ）^2-1/2sinα的最小值 已知sin=1/4,π/2 已知-π/6≤β≤＜π/4,3sin²α-2sin²β=2sinα,求sin²β-½sinα的最小值 已知sin(π-α)+sin(5π/2+α)=根号2/3(π/2 已知sin(3π+α)=2cos(α-4π)求cos(π/2 -α)+5sin(π/2 +α)/2cos(π+α)-sin(-α) 已知tan(π+α)=3,则2cos(π-α)-3sin(π+α)/4sin(α+π/2)+sin(2π-α)= 已知sin(a+π/4)sin(a-π/4)=1/3,若π/2 已知sin(α-β)=3/5,sin(α+β)=-3/5,π/2 已知sin(α+TT/3)+sinα=-4√3/5,-TT/2