Some derivatives are simplify-able, while others aren't. We usually want to simplify the answer a little, but we don't want to do unnecessary work. How do we know when to stop simplifying?
Soon, we'll be spending a lot of energy finding all the places where a particular derivative is zero or undefined. We want to simplify the derivative as much as possible. While we can't give any exact rules for when to stop simplifying, here are some tips that might be useful: