Question

Como se demuestra sec^4 X - sec^2 X = tan^4 X + tan^2 X

Answer 1

tan^2x+1=sec^2x
(tan^2x+1)^2=(sec^2)^2
tan^4x+2tan^2x+1=sec^4x
tan^4x+tan^2x+tan^2x+1=sec^4x
tan^4x+tan^2x+sec^2x=sec^4x
tan^4x+tan^2x=sec^4x-sec^2x