The function of
.
The domain of a function is set of all values of
, which makes the function mathematically correct.
The domain of the function is
.
The function is 
Limit definition of derivatives :
.

Consider
.


Substitute above result in equation
.

.
Denominator of the function should not be zero.
\
Domain is
.
The derivative of the function
is differentiable for
.
The derivative of the function
is differentiable for
.