Question

Решите пожалуйста, 100 баллов.

Answer 1

$B\Big(-\frac{\sqrt3}{2}\, ;\, \frac{1}{2}\, \Big)\\\\cosa=\frac{x}{OB}=\frac{-\sqrt3/2}{1}=-\frac{\sqrt3}{2}\approx -0,87\\\\sina=\frac{y}{OB}=\frac{1/2}{1}=\frac{1}{2}=0,5\\\\tga=\frac{y}{x}=\frac{sina}{cosa}=\frac{1/2}{-\sqrt3/2}=-\frac{1}{\sqrt3}=-\frac{\sqrt3}{3}\\\\B(cosa\, ;\, sina)$