I guess we can agree that $+0 = -0$. Now, after that, I was simply looking at some graphs. The graph of $\tan x$ shows asymptotes at x = $n\pi + \pi/2$. I got to thinking, what if they weren't asymptotes, but actually continuous lines?
If I take $0$ and ($+/-$)$\infty$ as diametrically opposite points of a circle, and sort of roll the $\tan x$ graph into a cylinder with the Y-axis as circumference and x-axis as the length of the cylinder, then $\tan x$ will become continuous.
This seems intuitively valid, but is there a formal proof possible that $+\infty=-\infty$? (Using simple mathematics, if possible. I am still in Grade 11)