Question

How do you find the vertex given `y=x^2 -4`?

Answer 1

The Vertex is (0,-4)

Explanation:

graph{x^2-4 [-10, 10, -5, 5]}

There are many ways to obtain the vertex, the most tedious one is by graphing. As shown above.

If you are into formulas, you can remember `(y-k)=(x-h)^2`, where the vertex is `(h,k)`. This formula is easily derivable, and you can probably find a proof for it in Wikipedia.