The function is
.
Differentiate on each side with respect to
.

Derivative of a logarithmic function :
.

Logarithm of a negative value is undefined.
\
Case 1: If both the terrms are positive then
.
and 
and
.
The condition is true for
.
Domain is
.
Case 2: If both the terrms are negative then
.
and 
and 
The condition is true for
.
Domain is 
Therefore the domain of the function is
.
.
The domain of the function is
.