Microsoft Word/Excel/Outlook, essay composition, math; I LOVE TO TEACH
The domain is negative infinity to positive infinity. The factor of x is the numerator, not the divisor. Therefore, it can be zero. It is also not being square-rooted. Therefore, it can be a negative number.
The range is different because x2 will render any value of x either zero or a positive number. We need to establish the minimum while recognizing there is no maximum.