sin^2a+cos^2(π/6+a)+1/2sin(2a+π/6)
sin^a+cos^(π/6+a)+1/2sin(2a+π/6)求值
(1-sin^6a-cos^6a)/(sin^2a-sin^4a)
化简:sin(-a)cos(2π+a)sin(-a-π)
已知2sin(a/2)=cos(a/2),则sin(a+π/6)=
求证 cos(A)+ 根号3sin(A)=2sin(π/6+A)
求值sin^2a+cos^2a(π/6+a)+1/2sin(2a+6/π)
化简Sin A + Sin 2A / 1+cos A +
sin(2π-a)cos(π/2-a)/cos(π-a)sin(π/2+a)
化简[cos(a-π)/sin(π-a)]sin(a-π/2)cos(π/2+a)=
化简sin(π+a)cos(-a)+sin(2π-a)cos(π-a)
化简 sin(2π-a)sin(π+a)cos-π-a) / sin(3π-a)cos(π-a)
化简(1-sin^6 a-cos^6 a)/(cos^2 a-cos^4 a)==