Question

Найдите sinα, tgα, ctgα, если cosα=3/4

Answer 1

$sin\alpha = \sqrt{1-(\frac{3}{4})^{2}} = \sqrt{\frac{7}{16}} = \frac{\sqrt{7}}{4}$

$tg\alpha = \frac{\sqrt{7}}{4} : \frac{3}{4} = \frac{\sqrt{7}}{3}$

$ctg\alpha = \frac{3}{4} : \frac{\sqrt{7}}{4} = \frac{3}{\sqrt{7}}$