Given:
The graph of the function is given.
To find:
The domain and range and check whether it is a function or not.
Step-by-step explanation:
Using the vertical line test, the vertical line crosses the curve exactly at one point.
So, it is a function.
It is the graph of the square root function.
The parent function is,

It is translated 4 units left. So, the function will be,

As we know, the domain is the set of all possible input values.
So, the domain of the function is,

As we know, the range is the set of all possible output values.
So, the range of the function is,

Final answer:
The domain and range are,

Yes, it is a function.