4.12. sin α = −12/13, π < α < 3π/2.

Question

Вопрос:

Accepted Answer

В III четверти cos α < 0.

\(\cos\alpha=-\sqrt{1-\frac{144}{169}}=-\frac{5}{13}\).

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

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

4.12. sin α = −12/13, π &lt; α &lt; 3π/2.