Question

dado senx= -3/5 e 180° a) cosx
b) cotgx

Answer 1

A) sen²x+cos²x=1  →Relação fundamental
(-3/5)²+cos²x=1
9/25-1=-cos²x
-16/25=-cos²x
16/25=cos²x
$\sqrt{16/25}$=cosx
4/5=cosx

B)cotgx=1/tgx
tgx=senx/cosx
(-3/5)÷(4/5)=tgx
-15/20=tgx
-3/4=tgx
cotgx=-4/3