Question

Sendo cos x = 4/5 ,com x no 3 quadrante,determine sen x e tg x.

Answer 1

senx=√1- cos²x=√1-(16/25)=√9/25= -3/5

tgx=senx / cosx

tgx= -3/5 / -4/5

tgx = -3/5 • -5/4

tgx = 3/4