$\"\"$

The function is $\"\"$ .

The domain of a function is set of all values of $\"\"$ , which makes the function mathematically correct.

The denominator of the function should not be zero.

$\"\"$

The domain of $\"\"$ is all nonzero real numbers except at $\"\"$ .

$\"\"$

Graph the function $\"\"$ .

$\"\"$

Observe the graph :

The derivative of the function $\"\"$ is discontinuous at $\"\"$ .

$\"\"$ is differentiable at $\"\"$ .

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$\"\"$ is differentiable at $\"\"$ .