Question

Решите пожалуйста !!!!

Answer 1

Ответ:

sin A = 2/3
$sin^{2}$ A + $cos^{2}$ A = 1 ⇒
$cos^{2}$ A = 1 - $sin^{2}$ A
cos A = $\sqrt{1-sin^{2}A }$
cos A = $\sqrt{1-(2/3)^{2} }$
cos A = $\sqrt{1-4/9}$
cos A = $\sqrt{9/9 - 4/9}$
cos A = $\sqrt{5/9}$
cos A = $\sqrt{5}/\sqrt{9}$
cos A = $\sqrt{5}/3$

tg A = sin A/ cos A = 2/3 ÷ $\sqrt{5} /3$ = 2/3 * 3/$\sqrt{5}$ = 2$\sqrt{5}$

ctg A = cos A / sin A =  $\sqrt{5} /3$ ÷ 2/3 = 3/$\sqrt{5}$ * 2/3 = 2$\sqrt{5}$

Объяснение: