4.8. sin α = 5/13, π/2 < α < π.

Question

Вопрос:

Accepted Answer

Во II четверти cos α < 0.

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

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

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

4.8. sin α = 5/13, π/2 &lt; α &lt; π.