4.5. cos α = −5/13, π < α < 3π/2.

Question

Вопрос:

Accepted Answer

В III четверти sin α < 0.

\(\sin\alpha=-\sqrt{1-\frac{25}{169}}=-\frac{12}{13}\).

\( g\alpha=\frac{12}{5}\), \(\ctg\alpha=\frac{5}{12}\).

Ответ: sin α = −12/13; tg α = 12/5; ctg α = 5/12.

4.5. cos α = −5/13, π &lt; α &lt; 3π/2.