What is the domain and range of the function

f(x)=x^2-2?

please teach me..!

as I mentioned in your previous post,

The domain of all polynomials is (-∞,∞)

Now, note that x^2 >= 0
so, x^2-2 >= -2

The range is thus [-2,∞)

Think of the graph. Its vertex is at (0,-2).