For live scripts, using the LaTex equations, how to represent the absolute value?

I am using live editor to write a document, in which I need to represent the absolute value of a function.

Answer 1

[Walter Roberson]

Apparently it is not easy to do "properly"; see https://tex.stackexchange.com/questions/43008/absolute-value-symbols

What might be good enough for your purposes is \left|EXPRESSION\right| such as

which is $ \left|sin(x)\right| $ without the space around the $