[tex]\it E(x)=sinx+\sqrt3cosx-tgx\\ \\ x=300^o \Rightarrow \begin{cases}\it sin300^o=-sin(360^o-300^o) = -sin60^o=-\dfrac{\sqrt3}{2}\\ \\ \it cos300^o= cos(360^o-300^o) = cos60^o=\dfrac{1}{2}\\ \\ \it tg300^o = \dfrac{sin300^o}{cos300^o}=\dfrac{-\dfrac{\sqrt3}{2}}{\dfrac{1}{2}}=-\sqrt3\end{cases}\\ \\ \\ E(300^o)=-\dfrac{\sqrt3}{2}+\sqrt3\cdot\dfrac{1}{2}-(-\sqrt3)=-\dfrac{\sqrt3}{2}+\dfrac{\sqrt3}{2}+\sqrt3=\sqrt3[/tex]
