The function is 
.
Horizontal line test:
\A function 
 has an inverse 
 if and only if no horizontal line intersects its graph of the function at most one point.
Graph :
\Graph  the function 
.
Draw the horizontal line 
.

Observe the graph:
\ The horizontal line 
 touches the graph of the function at only one point.
The function is an one-to-one, because it passes the horizontal line test.
\Therefore the inverse of the function exist.
\
.
To find the inverse of the function, consider 
 and solve 
 in terms of 
.  


Now interchange 
 and 
.

Replace 
.

The inverse of 
 is 
.
\
Find the domain of 
.  
For the rational function, the denominator of the function should not be zero.
\
   
Domain of the function 
 is 
.
Range of the function 
 is 
.
Find the domain of  
.
For the rational function, the denominator of the function should not be zero.
\
   
The domain of the function 
     is 
.   
Restrictions over the domain of 
     :
The domain of inverse funtion 
     is the range of the function 
.
Range of the function 
 is 
.
Hence the domain of 
     is 
.
Therefore the inverse of the function 
.
The domain of 
     is 
.