Respuesta :

konrad509
[tex]\sec\left(0-\dfrac{\pi}{2}\right)=\sec\left(-\dfrac{\pi}{2}\right)=\dfrac{1}{\cos \left(-\dfrac{\pi}{2}\right)}=\dfrac{1}{0}[/tex]

So, the function [tex]f(x)[/tex] for [tex]x=0[/tex] is undefined.