[tex] \sin(30) = \frac{1}{2} \\ \\ \cos(60) = \frac{1}{2} \\ \\ \sin(60) = \frac{ \sqrt{3} }{2} \\ \\ \cos(30) = \frac{ \sqrt{3} }{2} [/tex]
[tex] \frac{1}{2} \times \frac{1}{2} + \frac{ \sqrt{3} }{2} \times \frac{ \sqrt{3} }{2} = \\ \\ = \frac{1}{4} + \frac{3}{4} = \frac{4}{4} = 1[/tex]
Coroniță pls
