## 6.5. Differentiable Functions

### Examples 6.5.14(b):

This function is so easy that you should 'see' the answer right away by looking at a mental picture of the graph of the function. There are three local extrema ... all details are left to you. |

Note that this function is not differentiable at *x = 1* and
*x = -1*. Which of our theorems can we still apply ? Or does
none apply ?