If a function has a positive average rate of change on the interval
.
Formula for the average rate of change from to
is
.
Slope of a line could be interpreted as the average rate of change.
\ \Consider the two functions that have positive average rate of change on the interval .
Graph of : Graph of
:
Observe the above two graphs:
\The two example graphs satisfy , but the function
is not increasing on
.
And the function in increasing on
.
Therefore, the function has a positive average rate of change on the interval
, is not necessary increasing on
.
Not necessarily. It just means .