sin(π/6-α)=1/4,则sin(π/6+2α)=

sin(π/6-α)=1/4,则sin(π/6+2α)= 已知sinα（x+π/6）=1/4,则sin（5π/6-x）+sin（π/3-x）的平方=? 若sinα=1/2,则sin(π/4-α)cos(π/4-α)= sin(π/4+α)sin(π/4-α)=1/6 求sin2α 已知sin(π/6-α）=1/4,则sin(π/6+2α）=（）, 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 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 sin(π/4+α)sin(π/4-α)=1/4 求2sin^2(a) -1+tana-1/tan sin(α-π/4)=12/13,sinα= 若sin(α+β)=1/2,sinαcosβ=3/4,则sin(α-β)= 已知sin(x+π/6)=1/4,求sin(5π/6-x)+sin^2(π/3-x) 1-2sin²π/8=sinπ/4 2sinα-3cosα/4sinα-9cosα=-1,则9sin^2α-3sinαcosα-5= 为什么sin-sin^2=1/4 sin0=0 sin(1/6π)=1/2sin(1/3π)=√3/2sin(1/2π)=1sin(2/3π)=√3/2sin(5/6π)=1/2sin(π)=0sin(-π)=0sin(-5/6π)=-1/2sin(-2/3π)=-√3/2sin(-1/2π)=-1sin(-1/3π)=-√3/2sin(-1/6π)=-1/2sin(7/6π)=-1/2sin(4/3π)=-√3/2sin(5/3π)=-√3/2sin(11/6π)=-1/ 若sin (π/4+α)sin(π/4-α)=-1/8,则2sin²α+tanα-1/tanα-1的值为 已知α,β∈(0,π/2),且2tanα+3sinβ=7,tanα-6sinβ=1,则sinα=