Vertex Form
Vertex Form
Naming the Vertex
To find the vertex of an equation in vertex form, locate the h and k of the equation: y = a(x - h) 2 + k. Because the formula subtracts h, the x-coordinate of the vertex will have the opposite sign as the h in the equation. Since the formula adds k, the y-coordinate will have the same sign as the k in the equation.
Example 1 Name the vertex for the function, y = (x - 2)2 + 3.
The vertex is (2, 3).
Example 2 Name the vertex for the function, y = -2(x + 3)2.
The vertex is (-3, 0).
Example 3 Name the vertex for the function, y = -x2 - 4.
The vertex is (0, -4).