cos(π/6+α)=a,则cos(19/6π+α)= ,sin(19/6π+α)=
已知(3sinα+cosα)/(3cosα-sinα)=2,则2-3sin(α-3π)sin(1.5π-α)-[cos(
已知(sinα-cosα)/(sinα+cosα)=1/3,则cos^4(π/3+α)-cos^4(π/6-α)的值为
求证:[tan(2π-α)cos(3π/2-α)cos(6π-α)]/[sin(α+3π/2)cos(α+3π/2)]=
求证 cos(A)+ 根号3sin(A)=2sin(π/6+A)
已知2sin平方α-cos平方α+sinαcosα-6sinα+3cosα=0,求(2cos平方α+2sinαcosα)
sinα+sinβ=sinγ cosα+cosβ=cosγ 证明cos(α-γ)
sin(π/2+α)·cos(π/2-α)/cos(π+α)+sin(π-α)·cos(π/2+α)/sin(π+α)=
已知cos(π/2+α)=sin(α-π/2) 求sin(π-α)-cos(π+α)/cos(5π/2 -α)+2sin
已知cos(π/2-α)-2cosα=sinπ,且cosα<0,则sinα的值为?
已知α∈(π,2π) sinα+cosα=1/5 求sinα*cosα sinα-cosα
已知α=7/12π,那么cosα√(1-sinα)/(1+sinα)+sinα√(1-cosα)/(1-cosα)=
已知tan(3π+α)=2,求:1、(sinα+cosα)²;2、sinα-cosα/2sinα+cosα