**Section Objectives**

- Sketch the graph of .
- Sketch the graph of .

In this section, we return briefly to graphing lines and parabolas.

The simplest way to graph a linear function of the form is to recognize that the function form is a slope-intercept form.

The graph of is a line with slope and -intercept . To graph the line, plot the point and use the slope to obtain another point on the line.

- Sketch the graph of .

- Sketch the graph of .

The graph of is a parabola with vertex at . If is positive, the graph opens upward. If is negative, the graph opens downward. In either case, the -axis is a symmetry axis.

When graphing parabolas, you should plot a few points (besides the vertex) to pinpoint the precise shape.

- Describe the graph of .

- Sketch the graph of .