若sin(π/6-x)=1/3,则cos(2π/3+2x)= 具体过程.

若cos x-sin x = 0.5,则cos^3 x-sin^3 x = 已知sin[a-b]cos a-cos[b-a]sin a=3/5,b是第三象限角,求sin[b+5π/4]的值第一题1/2cos x-√3/2sin x第二题√3sin x+cos x第三题√2[sin x-cos x]第四题√2cos x-√6sin x 若sin x/2 - cos x/2 = 1/3,则sin x=? 若sin x/2-cos x/2=1/3,则sin x= 若f（sin x+cos x）=sin x·cos x,则f（cos 派/6）=? 若cos(x+y)cos(x-y)=1/3,则cos^x-sin^y=?^为平方 若sin(π+x)+cos(π/2+x)=-m,则cos（3π/2-π）+2sin（6π-x）=? 若方程12x²+πx-12x=0的两的根分别是α,β,则cosαcosβ-√3sinαcosβ-√cosαsinβ-sinαsinβ= sin（x-π/3）=1/3,则cos（x+π/6）=? sin(x+π/6)=1/2,则cos(π/3-x)求值 若sin(pai/6-x)=1/3,则cos(2pai/3+2x)=? 已知sinx+cosx=1/3,则sinxcosx=已知tanx=2,则sinx+cosx/sinx-cosx= sin^2x-cos^2x+sinxcosx=化简2sin^2x-1/1-2cos^2x=若sin(π/6-x)=a,则cos(2π/3-x)=已知sinα=3/5,α∈(π/2,π) cosβ=5/13,β∈(3π/2,2π),求cos(α-β)= 已知(1-cos x+sin x)/(1+cos x+sin x)=-2,若x不等于kπ+(π/2),则tan x= 若sin(π/6-x)=1/3,则cos(2π/3+2x)=___________ 若sin(π/6-x)=1/3,则cos(2π/3+2x)= 具体过程. cos(π/6-x)=sin(π/3+x)?为什么 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 若SIN X*COS X =1/3,已知0