How would you find the y-coordinate of the vertex of a parabola if you only have the equation

See below.

Step-by-step explanation:

If you have the vertex form of the equation, shown below, the vertex is at (h, k) so the y coordinate of the vertex is k:

y = a (x - h) ^2 + k.

If the equation of the parabola is in standard form you can find it by converting to vertex form;

Find the vertex of the parabola y = x^2 - 2x - 10:-

y = x^2 - 2x - 10 Completing the square:

y = (x - 1) ^2 - 1 - 10

y = (x - 1) ^2 - 11

The vertex is at (1, - 11).

y - coordinate is - 11.