Shown below is the graph of [math], NOT the graph of [math]. (Click on the picture for a better view.)
Graph of a derivative.
From the information in this graph we can conclude that a good approximation to [math] is

Shown below is the graph of a different function, [math]. (Click on the picture for a better view.) Indicate the labeled point at which
[math] changes sign:
[math] changes sign:
[math] changes sign:
Graph of a function.