The equation is .

To find the equation of the axis of symmetry.

The equation is compared to , then a = 1, b = 4 and c = – 9.

The equation for the axis of symmetry of a parabola: .

                                      (Substitute a = 1, and b = 4)

                                              (Simplify)

The equation of the axis of symmetry is .

To find the coordinates of the vertex.

Since the equation of the axis of symmetry is .

The vertex lies on the axis, the x-coordinate for the vertex is –2.

    (Substitute )

                                            (Simplify)

                                                  (Subtract: )

Then the vertex is at (–2, –11).

To Identify the vertex as a maximum or minimum.

Since the coefficient of the term is positive.

The parabola opens upward and the vertex is a minimum point.

The equation of the axis of symmetry is and symmetry choose x = 2.

To find the y-coordinate that satisfies the equation .

                 (Substitute x = 2)

                                                   (Simplify)

                                                               (Subtract: )

The coordinate point is (2, 3).

Since the graph is symmetrical about its axis of symmetry , and find another point on the other side of the axis of symmetry.

The point at (2, 3) is 4 units to the right of the axis.

Go 4 units to the left of the axis and plot the point (–6, 3).

Repeat this for several other points. Then sketch the parabola.

To graph of the function .

Use these ordered pairs to graph the equation.

1.    Use the symmetry of the parabola to upward the graph.

2.    Draw a coordinate plane.

3.    graph the vertex and the axis of symmetry.

4.    Plot the points.

5.    Draw a line through these points.

To graph of the function .

The solution of graph.