[v4vvdq]

I was also looking for this. And would like to add: lim(-1/x)_x -> 0 = -inf That is (in my opinion) the whole point why it is actually undefined. On one side of the y-axis it goes to infinity, on the other to minus infinity. I don't see a solution to this and therefore always have accepted that it is undefined.

[lupire]

No. 1/x^2 is undefined at 0 but has the same limit behavior, because limit behavior is not a function from "pairs of (functions from R to R, R)" to R

Infinity is not a real number.

[ganzuul]

Can limit behavior be defined as Cauchy sequences?