Question

Dado sen x=3/5, calcule a cossec x e o cos x

Answer 1

a) Calculando a cossecante:
$cossec\ x= \frac{1}{sen\ x}$
$cossec\ x= \frac{1}{sen\ x}$
$cossec\ x= \frac{1}{3/5}$
$cossec\ x=1*5/3$
$cossec\ x= \frac{5}{3}$

b)Calculando o cosseno:
Pela relação fundamental da trigonometria:
$sen^2\ x+cos^2\ x=1$
$( \frac{3}{5} )^2+cos^2\ x=1$
$\frac{9}{25}+cos^2\ x=1$
$cos^2\ x=1- \frac{9}{25}$
$cos^2\ x= \frac{16}{25}$
$cos\ x= \sqrt{ \frac{16}{25}}$
$cos\ x= \frac{ \sqrt{16}}{ \sqrt{25}}$
$cos\ x= \frac{4}{5}$