Our definition of the derivative at a point works but it can be pretty tedious when we need to find multiple values. In this section, we're going to resolve this problem by seeing how we can find the derivative as a function rather than just an individual numeric value.

# Video Lectures

Our definition of a derivative does what we need it to but, like the definition of a limit, it isn't the easiest thing to use in practice. The remainder of this chapter is going to be spent coming up with tools and formulas that make finding the derivative easier. In this lecture, we're going to take a step back from finding the derivative *at a point* and see how we can find the derivative as a function or formula.