因为cos2x=2cos^2x-1;sin2x=2(sinx)(cosx)所以f(x)=cos^2x+(根号3)sinx * cosx=(cos2x+1)/2+[(根号3)(sin2x)]/2因为1/2=sin(30度）；(根号3)/2=cos(30度)所以原式=[sin(30度)](cos2x)+[cos(30度)](sin2x)+1/2=sin(2x...