The function is
.
The function is differentiable for all values of
if
.
Consider right hand limit
.

.
Consider right hand limit
.

The function is differentiable for all values of
then
.

Substitute
in the function.
The function is
.
The function is
.
If the function is differentiable on all values of
, then it continuous for all values of
.
The function is continuous for all values of
if
.
Consider right hand limit 
.
Consider right hand limit
.

.
The function is continuous for all values of
if
.

Substitute
in the function.

The values of
and
are
and
respectively.
The values of
and
are
and
respectively.