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In this lesson, you will learn how the vertex, maximum value or minimum value, and intercepts can help you create the graph of a quadratic function.

Vertex/Minimum Value/Maximum Value

Recall that a parabola is the graph of a quadratic function.

Parabola opening up

For a parabola which opens up, the lowest point on the parabola is the vertex.

Graph of parabola opening up, vertex at (-2,-3)

Notice that the y-coordinate of the vertex is the minimum y-value for this function.

For a parabola which opens up, the y-coordinate of the vertex is the minimum value.

For a parabola which opens down, the highest point on the parabola is the vertex.

Notice that the y-coordinate of the vertex is the maximum y-value for this function.

For a parabola which opens down, the y-coordinate of the vertex is the maximum value.

Parabola opening downward

Name the vertex for the parabola below. Then state whether the y-coordinate of the vertex is the minimum or maximum value.