## Algebra 2 (1st Edition)

$\dfrac{\tan x+1}{1-\tan x}$
In the given problem, the wrong formula is used because a mistake was made in the denominator. Now we will write the correct formula. $\tan (x+\dfrac{\pi}{4}) = \dfrac{\tan x+\tan \dfrac{\pi}{4}}{1-\tan x \tan \dfrac{\pi}{4}}$ or, $= \dfrac{\tan x+1}{1-\tan x}$