sin(6/π-α)=1/3,则cos(2π/3+2α)的值为
已知(sinα-cosα)/(sinα+cosα)=1/3,则cos^4(π/3+α)-cos^4(π/6-α)的值为
若sinα-sinβ=1-根号3/2,cosα-cosβ=-1/2,则cos(α-β)的值为
已知cosα-sinα=(-根号3)/2,则sinα*cosα的值为
sin^2(α)+cosαcos(π/3+α)-sin^2(π/6-α)为定值,要证明
已知tan(3π-α)=2,则sin(-3π+α)+cos(π-α)/-cos(π+α)+sin(-α)的值为
sin(6/π-α)=1/3,则cos(2π/3+2α)的值为
已知sinα+3cosα=2,求(sinα-cosα)/(sinα+cosα)的值
已知tan(π-α)=2,求sinα-2sinαcosα-cosα/4cosα-3sinα的值
已知cos(π/2-α)-2cosα=sinπ,且cosα<0,则sinα的值为?
已知(3sinα+cosα)/(3cosα-sinα)=2,则2-3sin(α-3π)sin(1.5π-α)-[cos(
cos(π/3-α)=1/8,则cosα+(根号3)sinα的值为____
求证sin^2α+cosαcos(π/3+α)-sin^(π/6-α)的值与α无关