You can determine the derivative of a function by letting approach to in the difference quotient:
You can use this to set up some general rules that make it easier to determine the derivatives of a lot of functions. These are called the differentiation rules and applying these rules is called differentiating.
Differentiation rule 1 (the power rule):
The derivative of is for every value of and for positive integer values of .
Differentiation rule 2 (the constant rule):
The derivative of a constant (function) is : if then .
Differentiation rule 3 (the sum rule):
The derivative of a sum (or difference) of two functions is the sum (or difference) of the derivatives of these functions: if then .