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

The domain of a function is all values of $x$ that can be put in without getting an undefined answer. In your case if we think about it is there any value of $x$ that would 'break' the equation? No there is no so the domain of the function is all real values of $x$ which is written as $x \in \mathbb{R}$.
The range of a function is the range of possible values $y$ could become. In your case we have an ${x}^{2}$ which means we can never have a negative value of ${x}^{2}$. The lowest value of ${x}^{2}$ we can have is 0, if we put in an $x$ value of 0.
Given there is -2 on the end of the equation this means the lowest possible value of $y$ we can get is -2, meaning the range of the function is: $y \ge - 2$