$\"\"$

The function is $\"\"$ .

Graph the function $\"\"$ .

$\"\"$

Observe the graph:

The function is continuous at $\"\"$ .

The function $\"\"$ is not continuous at every non zero integer.

The function $\"\"$ has non-removable discontinuity at every integer except $\"\"$ .

$\"\"$

The function $\"\"$ has non-removable discontinuity at every integer except $\"\"$ .