已知sin(α+π/6)=-5/13,3π/2＜α＜2π 则cosα=

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) .已知sin（α+π／6）=3／5,π／2＜α+π／6＜π,求sinα 已知sin(2α-β)=3/5,sinβ=-12/13,且α∈（π/2,π),β∈(-π/2,0)求sinα 已知cos(α-π/6)+sinα=3√3/5,则sin(α+7π/6)=? 已知sin(α-π/4)=5/13 阿尔法∈(3π/4,π/4).求sinα的值 已知cos(α-π/6)+sinα=(4倍根号3)/5,则sin(α+7π/6)= 已知sinα（x+π/6）=1/4,则sin（5π/6-x）+sin（π/3-x）的平方=? 已知sin(π-α)+sin(5π/2+α)=根号2/3(π/2 已知sin(3π-α)=-2sin(π/2+α)则sinαcosα 已知sin(α+π/3)+sinα=-4√3/5(-π/2 已知sin(α-β)=3/5,sin(α+β)=-3/5,π/2 已知sin(π/6-a)=根号3/3,则sin(5π/6+a)= sin（-19π/6）=?已知[3Sin(π+a)+Cos(π-a)]/4Sin(-a)-Sin(5π/2+a)=2，求tan a 已知sin(π/4-α)=5/13,0 已知sin(π/4-α)=5/13,0 已知sin(（π/4）-α)=5/13,(0 已知sin（2α+ β）=5sinβ,求证：2sin（α+ β）=3sinα