The Piecewise function is $\"\"$ .

The function is differentiable for all values of $\"\"$ .

Now consider that function is differentiable at $\"\"$ .

$\"\"$ .

$\"\"$

If the function $\"\"$ is differentiable at $\"\"$ , then it is continuous at $\"\"$ .

Left hand limit is equal to right hand limit of the function at $\"\"$ .

$\"\"$

Substitute $\"\"$ in the above expression.

$\"\"$

$\"\"$ and $\"\"$ .