Any function can be graph. When a function is differentiated, a derivative function is the result. This derivative function can be graphed, and features of the derivative graph may tell us something about the original graph. In particular, we can identify stationary points and determine their nature.
Suppose a functionhas derivative
the graph of which is sketched below.
At the point A,so the point A is a stationary point for
Since
the point A is a maximum.
At the point B,so the point B is a point of inflection for
Since
the point B is a non stationary point of inflection.
At the point C,so the point C is a stationary point for
Since
the point C is a minimum.
The graph below has three points of inflexion.
At the point A,so the point A is a point of inflexion for
Since
the point A is a non stationary point of inflexion.
At the point B,so the point B is a point of inflection for
Since
the point B is a stationary point of inflection.
At the point C,so the point C is a point of inflexion for
Since
the point A is a non stationary point of inflexion.