The formula for the average value of a function f over the interval from a to b is. So the average or the mean value of f x on ab is defined by f 1 ba b a f xdx. The graph on the left shows a rectangle whose area is clearly less than the area.
Then the average value of a function on an interval is the height of a rectangle that has the same width as the interval and has the same area as the function on that interval.
You can find the average value of a function over a closed interval by using the mean value theorem for integrals. The average is one measure of the center of a set of data. The argument may include numbers or names arrays or references that contain numbers. So if youre looking for the average value of f on that interval it wont do any good to try adding up those infinitely-many data points.