[tex]=\frac{3\cdot \frac{\sqrt3}{3}-4\cdot\frac{\sqrt3}{2}}{(\frac{\sqrt3}{2})^2+(\frac{\sqrt2}{2})^2}=\\\\\frac{\sqrt3-2\sqrt3}{\frac{3}{4}+\frac{2}{4}}=\frac{-\sqrt3}{\frac{5}{4}}=-\frac{4\sqrt3}{5}[/tex]
