Respuesta :

HomertheGenius
[tex] \lim_{x \to \pi /4} \frac{tan x - 1}{x- \pi /4} = \frac{0}{0} [/tex]
With L` Hospital`s Rule ( ( tan x ) ` = 1/ cos^2 x ) :
[tex] \lim_{x \to \pi /4} \frac{1}{cos ^{2} x} = \\ = \frac{1}{cos ^{2} ( \pi /4)} = \\ \frac{1}{1/2} [/tex]   =  2