Question

Sinα = -0.7, если 3Π:2<α<2Π. Найти: cosα, tgα, ctgα

Answer 1

$sin\alpha=-0,7;\frac{3\pi}{2}\ \textless \ \alpha\ \textless \ 2\pi=\ \textgreater \ \alpha\in IV\\cos\alpha=\sqrt{1-0,49}=\sqrt{0,51}\approx0,71\\tg\alpha=\frac{sin\alpha}{cos\alpha}=\frac{-0,7}{\sqrt{0,51}}\approx-0,98\\ctgx=\frac{1}{-0,98}\approx-1,02}$