There are basically two types of shortcuts for finding derivatives: derivative formulas and differentiation rules.
A derivative formula uses the formula for a simple function (i.e., no extra operations) to tell you the formula of the derivative function. These are rules like or .
A differentiation rule tells us how the differentiation operator interacts with function operations like addition, subtraction, and constant multiples. (Later we will also learn rules for composition, multiplication, and division.) For example,
Notice that we don't need to know what f and g are to use this rule; it applies to the operation "+", not the particular functions being added together.