Question

Simplifique as expressões: 
   y= senx . cossecx -1
      ---------------------------
               tg x

Answer 1

$y=\frac{senx.cossecx-1}{tgx}=\frac{senx.\frac{1}{senx}-1}{tgx}=\frac{1-1}{tgx}=\frac{0}{tgx}=0$