Question

(1-sen 2 x) sec 2 x =1

Answer 1

(1 - sen 2x) = cos 2x
sec 2x = 1 / cos 2x

cos 2x / cos 2x = 1
1 = 1

ó si este es tu ejercicio

(1 - sen(^2)x) sec(^2)x = 1
cos(^2)x / cos(^2)x = 1
1 = 1