why are the vertex coordinates (h,-k)?

Question

Since the standard form of a quadratic equation is y=a[x-h]^2+k , why are the coordinates for the vertex, (h, -k)? Shouldn't they be (-h, k)?

Answer 1

None of the above.

Given the equation of a parabola:

y = a(x - h)² + k

The vertex is (h, k).
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If you subtract k from both sides you would get:

y - k = a(x - h)²

This is the same parabola so the vertex is still (h, k).