So I came upon something that I thought was interesting, and my google search didn't come up with a good answer.
Say you have some function $f(x)$. Where does evaluating $f(x)$ come in the order of operations? PEMDAS says that things in Parenthesis come first, so in $(3+2)-6 \times 8$, $(3+2)$ would be evaluated first, but what about for our function $f$? if $f(x) = x\times 8$, and we inserted it into our example as $(3+2)-f(6)$, does PEMDAS still hold? What is evaluated first?
I've also seen other functions like $\sin$ written both as $\sin(\theta)$ and $\sin \theta$. In this case, is $\sin \theta $ evaluated after $(3+2)$? Or is $\sin(\theta) \equiv \sin \theta$?