So my question is fairly simple, and it MUST've been asked multiple times before, but i had no luck using the search tool to find any results matching my question; or at least not any ones with answers that seemed to work.

For Maple 2019

Whenever i want to define a new function g(x) as the derivative of the function f(x), that is

f(x) := 3*x + 2
g(x):= f'(x)
g(3) --> Error

This is an annoyance almost every day of working with Maple for my engineering studies, and while i accidentally found a workaround for integrals, i need to figure out how to use derivatives in my expressions without needing to copy+paste the outputs.

Bonus question: why is the x in the derivative seen as a variable and not an operator? An