Question

What is the domain and range of `f(x) = 2x^2 - 3`?

Answer 1

graph{2x^2-3 [-10.07, 9.93, -3.86, 6.14]} So this shown above `uarr` is the graph for `f(x)=2x^2-3`.
Domain: `x=oo`
Range: `y > -3`

Explanation:

The definition of domain is the set of `x` values on the graph. The definition of the range is the set of `y` values on a graph.
So when you look at the domain you look at the `x`-axis (horizontal line). So where does the line stop and start on the `x`-axis? it goes on forever right? Because the side keeps expanding forever and ever so the domain would equal `oo` ... Now let's look at the range. The range is the set of y-values so if you have a paper on this tilt it so it's easier to see it looks like a big arrow, <. So the tip of this "arrow" touches -3 and then goes on forever and ever...
so you can either put y>-3 (y is bigger than negative 3) or,
`-3 < y < oo` (-3 is smaller than y but goes on forever).
Hope this was understandable please comment below if you have concerns...