$$\color{rgb(0,0,0)}\vec{i}$$

$$\color{rgb(0,0,0)}\vec{j}$$

$$\color{rgb(0,0,255)}\Rightarrow \theta=0$$

$$\color{rgb(0,0,0)}M \left( {cos(\theta) };sin(\theta) \right)$$

$$\color{rgb(0,0,255)}\Rightarrow \theta = \frac{\pi}{6}$$

$$\color{rgb(0,0,255)}\Rightarrow \theta=\frac{\pi}{4}$$

$$\color{rgb(0,0,0)}M$$

$$\color{rgb(0,0,255)}\displaystyle \frac{1 }{2 }$$

$$\color{rgb(0,0,255)}\displaystyle \frac{\sqrt{3} }{2 }$$

$$\color{rgb(127,0,0)}\frac{\pi }{3 }$$

$$\color{rgb(0,0,255)}\begin{array}{l} {\displaystyle cos\left( {\frac{\pi }{3 } } \right) = \frac{1 }{2 } } \\ \displaystyle {sin\left( {\frac{\pi }{3 } } \right) = \frac{\sqrt{3} }{2 } } \end{array}$$

$$\color{rgb(0,0,255)}\Rightarrow \theta = \frac{\pi}{3}$$

$$\color{rgb(0,0,255)}\Rightarrow \theta=\frac{\pi}{2}$$

$$\color{rgb(0,0,255)}\Rightarrow \theta=\frac{2\pi}{3}$$

$$\color{rgb(0,0,255)}\Rightarrow \theta=\frac{5\pi}{6}$$

$$\color{rgb(0,0,255)}\Rightarrow \theta=-\frac{\pi}{6}$$

$$\color{rgb(0,0,255)}\Rightarrow \theta=-\frac{\pi}{4}$$

$$\color{rgb(0,0,255)}\Rightarrow \theta=-\frac{\pi}{2}$$

$$\color{rgb(0,0,255)}\Rightarrow \theta=-\frac{\pi}{3}$$

$$\color{rgb(0,0,255)}\Rightarrow \theta=\pi$$

$$\color{rgb(0,0,255)}\Rightarrow \theta=-\frac{2\pi}{3}$$

$$\color{rgb(0,0,255)}\Rightarrow \theta=-\frac{5\pi}{6}$$

$$\color{rgb(0,0,255)}\Rightarrow \theta = \frac{3\pi}{4}$$

$$\color{rgb(0,0,255)}\Rightarrow \theta=-\frac{3\pi}{4}$$