use the graph of the function $f(x)$ shown below in order to determine all values of $x$ in the interval $-9…

use the graph of the function $f(x)$ shown below in order to determine all values of $x$ in the interval $-9 < x < 9$ where the function is not differentiable.
Answer
Explanation:
Step1: Recall non - differentiability conditions
A function is not differentiable at points of discontinuity, sharp corners, and vertical tangents.
Step2: Identify discontinuities
From the graph, there are jump - discontinuities at (x=- 6) and (x = 1).
Step3: Identify sharp corners
There are no sharp corners in the given graph.
Step4: Identify vertical tangents
There is a vertical tangent at (x = 4).
Answer:
(x=-6,1,4)