The domain is the x-axis and the range is the y-axis.
To find the domain, you measure or count the widest part of this oval horizontally. So that is 3 units to the right of 0 and 3 units to the left of 0. I counted it exactly on the axis because that is the widest part of the oval.
To find the range, you again count or measure the widest part of the oval vertically. So that is 4 units above 0 and 4 units below 0.
