
William W. answered 04/15/20
Top Algebra Tutor
The "generic" vertex form is y = a(x - h)2 + k where the vertex is the point (h, k) and the vertical stretch is the "a" value. Additionally, a negative in front of the a will reflect the graph across the x-axis. Since the vertex is the point (h, k), the "h" is the horizontal shift and "k" is the vertical shift. The reason for that is that the vertex of y = x2 is at the origin (0, 0) and since the vertex essentially becomes the "new origin", the shift is "h" in the x-direction and "k" in the y-direction.
At any rate, this makes the vertex form:
y = -2(x - 0)2 + 3 or I suppose you could write it like this:
y = -2x2 + 3 but this isn't as obviously in vertex form as the other