$\"\"$

The functions are $\"\"$ and $\"\"$ .

Graph :

Graph the functions $\"\"$ and $\"\"$ .

$\"\"$

The function $\"\"$ is has horizontal tangent line and is differentiable at $\"\"$ .

The function $\"\"$ has sharp edge at $\"\"$ , hence it is not differentiable at $\"\"$ .

The function $\"\"$ is not differentiable at $\"\"$ .

$\"\"$

The function $\"\"$ is not differentiable at $\"\"$ .