tan11π/*6cos(-25π/6)*sin(-23π/6)
tan11π/*6cos(-25π/6)*sin(-23π/6)
确定cos7/12π,sin(-465°),tan11/3π,sin3*cos4*tan5的符号
1.化简sin²α+cosαcos(π/3+α)-sin²(π/6-α)
sin^2(α)+cosαcos(π/3+α)-sin^2(π/6-α)为定值,要证明
求证sin^2α+cosαcos(π/3+α)-sin^(π/6-α)的值与α无关
求证 cos(A)+ 根号3sin(A)=2sin(π/6+A)
化简sin(25π/12)cos(11π/6)-cos(11π/12)sin(5π/6)的值是
sin(-4π/3)cos(-23π/6)tan(25π/4)=?
tan(13π/3)+sin(-5π/2)+cos(-23π/6)
已知(sinα-cosα)/(sinα+cosα)=1/3,则cos^4(π/3+α)-cos^4(π/6-α)的值为
求值:sin(-3分之19π)+cos(-6分之25π)=?
cosπ/6+根号3sinπ/6=?