What is the formal definition of a derivative?
1 Answer
May 29, 2015
The formal definition of derivative of a function
The meaning of this is best understood observing the following diagram:
The secant PQ represents the mean rate of change
If you want the rate of change, say, at P you "move" point Q (and the secant with it) to meet point P as in:
In doing so you must reduce
Hope it helps!