Question

Se senx = 2/3, calcule cos x, tg x e sec x.

Answer 1

senx^2+cosx^2=1

cosx^2=1-senx^2

cox^2=1-(2/3)^2

cosx^2=1-4/9

cosx^2=9-4/9

cosx^2=5/9

cosx=√5/9
__________
cosx=√5 /3

tgx=senx/cosx

tgx=2/3 / √5/3

tgx=2.3/3√5

tgx=2/√5
_________
tgx=2√5/5

secx=1/cosx

secx=1/√5/3

secx=3/√5

__________
secx=3√5/5

espero ter ajudado!

boa tarde!