若sin(π /6-a)=1/3,则cos(2π /3+2a)=__________

若sin(π/6-a)=根号3/3,则sin(7π/6-a)= 若函数sin(π/3+a)=2/3,则sin(π/6+2a)= 已知平面向量a=(cosα,sinα),b=(cosβ,sinβ),若a=入b,则实数入的值为?=co, 若sin(π/6-a)=a,则sin(5π/6+a)= 1-sin a+sin a的平方-sin a的立方+……若a是正锐角,且sin a-cos a=0.5,求1-sin a+sin^2a-sin^3a+…… 已知sin(π/6-a)=根号3/3,则sin(5π/6+a)= 若sin(π/6-a)=1/3 则cos(2π/3+3a)=? 已知sin(a+π/4)sin(a-π/4)=1/3,若π/2 若sin(π-a)=2/3,则sin(2π-a)等于多少 若sin(π/6-a)=1/3,则cos(π/3-2a)=? 若cos(π/3+a)=-1/3 则sin(a-π/6)= 若sin(6/π-a)=1/3则cos(π/3+a)=? 若sin(π/6-a)=1/3,则cos(π/3+a) 若cos(a+π/3)=1/4,则sin(a-π/6)的值为 若sin(π+α)+sin(-α)=-m,则sin（3π+a)+2sin(2π-a)的值为? 若cos(π/6-A)=A,则sin（2π/3-A)为什么等于A? 已知向量a=(sin(α+π/6),1),b=(4,4cosα-根号3),若a⊥b,则sin(α+4π/3)等于 设角a=-35π/6,则2sin(π+α)cos(π-α)-cos(π+α)/ 1+sin^2α+sin(π-α)-cos^2(π+α)sina=sin(-35π/6)=sin(-6π+π/6)=1/2 cosα=根号3/22sin(π＋α)cos(π-α)-cos(π+α)/ [1+sin^2α+sin(π-α)-cos^2(π+α)]=2（-sinα)(-cosα）+cosα/[1+sin²