已知sina=(√5-1)/2,则sin2(a-π/4)=

已知sina=1/2计算sin(5派-a) 已知(sina+cosa)/(sina-cosa)=3 则2sin'a+(sina-cosa)'=? 已知sinA=1/5,求2sin(A+B)cosA-sin(2A+B) 已知(sina+cosa)/(sina-cosa)=2,则：(3sina+cosa)/(2sina+3cosa)=?sin^2a-2sinacosa+1=? 已知sin(π+a)=1/3,则sina= 已知sina=-1/3 则sin(a+x)= 1:已知sina+cosa=根2求sina cosa sin(4方)a+cos(4方)的值2:已知:sina+cosa=1/5(0 已知cosB = cos θ*sinA,cosC = sinθ*sinA.θ为已知角.则sin^2 A + sin^2 B +sin^2C等于多少? 已知sina-2sina=0,求sin2a-cos2a/1+sin平方a 已知sina=3sina （1）求sina *cosa的值 (2)求2sin^2a-3sinacosa-5 已知sina+3cosa/3cosa -sina =5,则sin平方a-sina*cosa的值是? 已知sin a+cos a=1/2 sina*cosa=?cos a/sina+sina/cosa=? 化简：sin(a-B)cosa-1/2[sin(2a+B)-sinB]=?已知cos(a-π/6)+sina=4√3/5则sin（ a+π/6)的值? sin(a-B)cosa-1/2[sin(2a+B)-sinB]=?已知cos(a-π/6)+sina=4√3/5则sin（ a+π/6)的值? 已知sina=3/2sin^2α+sin^2β,则函数y=sin^2α+sin^2β的值域为1 已知3SIN^2A+2SIN^2B=5SINA,求SIN^2A+SIN^2B范围 已知sin(a+π/3)+sina=-4√3/5,-π/2 已知sin(a+π/3)+sina=-4√3/5,-π/2