Are you really wanting MathJax? Or do you want mathematical expressions expressed like math? Does it have to be MathJax which is for browsers or can it be LaTeX?

Have you seen this topic

There are a few different reasonable answers in that topic.

mathjax, or an equivalent rendering in the browser it’s mostly about readability the answers in the browser.
Thanks for the link, It seems to have been the same issue!

One nice item of note about the other topic is that it is no longer generating lots of replies which I hope is do to providing a sutiable answer.

In a few days if you have a reasonable solution to your GPT-4 problem can you post some feedback here. As I do not have access to GPT-4 yet I am curious to know if something diffferent has to be done to see mathematical expression when using GPT-4.

Also curious to know if GPT-4 has access to plugins, specifically the Wolfram Alpha plugin. AFAIK as of 03/30/2023 the answer is no but if and when GPT-4 has acces to the Wolfram Alpha plugin it would be nice to know.