Question

Sendo x um arco do 3° quadrante e sen x = 3/5, calcule:        a) cos x     b) tg x     c) sec x      d) cossec x

Answer 1

sen x = 3/5, calcule:

a) cos x 
[tex]sen^2(x)+cos^2(x)=1 .: (\frac{3}{5})^2+cos^2(x)=1.:cos^2(x)=1-\frac{9}{25}=\frac{16}{25}.:cos(x)= \sqrt{\frac{16}{25}}=\frac{4}{5}[\tex]

b) tg x
[tex]tg(x)=\frac{sen(x)}{cos(x)}=\frac{\frac{3}{5}}{\frac{4}{5}}=\frac{3}{4}[\tex]

c) sec x
[tex]tg(x)=\frac{1}{cos(x)}=\frac{1}{\frac{4}{5}}=\frac{5}{4}[\tex]

d) cossec x
[tex]tg(x)=\frac{1}{sen(x)}=\frac{1}{\frac{3}{5}}=\frac{5}{3}[\tex]