Question

(1+senx) ( 1- senx) . sec x

Answer 1

Explicação passo-a-passo:

$= (1 + sen(x))(1 - sen(x)).sec(x)$

$= 1 - sen(x) + sen(x) - {sen}^{2} (x). \frac{1}{cos(x)}$

$= 1 - {sen}^{2} (x). \frac{1}{cos(x)}$

$= {cos}^{2} (x). \frac{1}{cos(x)}$

$= cos(x)$