Identify the extreme values, maxima, and minima of the following chart:
![451_Identify the extreme values.png](https://secure.tutorsglobe.com/CMSImages/451_Identify the extreme values.png)
Draw a tangent line at each of the points you labeled. What is the slope of the tangent line at such points? Derive a rule relating the slope of the tangent line at extrema. Share your rule with the class!