In this case, we'll have to carry out several steps to find the solution.
Step 01:
Data:
(1 + tan x)^2 = sec^2 x + 2tan x
Step 02:
trigonometric identity:
(1 + tan x)² = sec² x + 2tan x
(1 + tan x)² = 1² + 2tan x + tan x ²
= 1 + 2 tan x + ( sec ² x - 1)
= 1 + 2 tan x + sec ² x - 1
= sec ² + 2tan x
sec ² + 2tan x = sec ² + 2tan x
That is the full solution.