Here’s an example of an embedded pre-made Desmos graph in which I tasked students with identifying limit behavior at certain points. I also used LaTex code to type the limits into the equation editor. Actually I copied it and pasted it after the first one, then just modified it. Feel free to explore the embedded desmos, and use of LaTex inside the equation editor.

https://goformative.com/clone/ZTBEWB

To see the latex for infinity symbols and limits look here:

https://www.sharelatex.com/learn/Integrals,_sums_and_limits