Let be a function that satisfies the hypothesis:
- is continuous on the closed interval
-  is differentiable on open interval 
Then there is a number  in  such that:
 This can be used to find the mean value of the function This can be used to find the mean value of the function
Let f be a function that satisfies the hypothesis:
 This can be used to find the mean value of the function
This can be used to find the mean value of the function