Question

Aratati ca sin x = 3/5, stiind ca x apartine (0, pi/2) si cos x = 4/5.

Answer 1

daca $cosx= \frac{4}{5}$
atunci $sinx= \sqrt{1- cos^{2}x }= \sqrt{1- \frac{16}{25} }= \sqrt{ \frac{9}{25} }= \frac{3}{5}$
ceea ce trebuia de aratat