# What is the domain and range of y =2x^2 - 5x?

The domain is the set of $x$ values for which the function is valid, and the range is the corresponding set of $y$ values.
In this example, there are no restrictions on the value of $x$ so the domain is the set of all real numbers, and potentially all complex numbers as well if the expression does not need to be restricted to being able to be graphed.