已知sin(π+α)=根号3/2,求sin(3/4π-α)

已知sin(π+α)=根号3/2,求sin(3/4π-α) 已知sin(π/4+α)+sin(π/4-α)=根号2/3,（1）求sinα（2）求sin（α-π/4）/1-sin2α 已知sin(π/6+a)=（根号3）/3,求sin(2π/3+a)? 1、已知2根号3sin^2α+(2根号2-根号3)sinαcosα-根号2cos^2α=0,α∈(π/2,π),求sin 已知sin(π-α)-cos(π+α)=根号2分之4,求sin(π+α)+cos(3π-α)的值 已知：sin(α+π/3)+sinα=负5分之4根号3 α∈（-π/2,0）求cosα 已知sin(π-α)-cos(π+α)=根号2/3 求下列各式的值 已知sin(A+π/4)+sin(A-π/4)=根号2/3 1.求sinA的值 2.求【sin(A-π/4)】/【1-c 已知 cos π/5 =(根号5 +1）/4 求 sin π/5,sin -π/5 ,sin 4π/5 ,sin 3π/ 已知函数f(x)=sin^2 x+2根号3sinxcosx+sin(x+π/4)sin(x-π/4),x属于R,求f(x 已知sin (α+派/3）+sinα=-4根号3/5,-派/2 已知tanα=2,sinα+cosα＜0,求[sin(2π-α)*sin(π+α)*cos(-π+α)]/[sin(3π