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.
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.