Respuesta :

Answer:

see explanation

Step-by-step explanation:

using the identity

tan²x = sec²x - 1

consider the left side

(tanx + secx)² ← expand using FOIL

= tan²x + 2tanxsecx + sec²x

= sec²x - 1 + 2tanxsecx + sec²x ← collect like terms

= 2sec²x + 2tanxsecx - 1

= right side , thus proven