


Enter the equations you want to plot together with the color of each plot. Then specify the variables appearing in the equations and their limits, set the options if necessary and click the Plot button.
GRAPHING EQUATIONS
As we have already seen, illustrations such as scatterplots and lines of best
tit play an important role in helping us investigate the relationship between
two quantities. In the case where the relationship between two quantities is
described by a two variable equation, it is often desirable to represent this
relationship geometrically with a graph. We restate a definition from earlier. Graphing an Equation by Plotting Points Since the given equation clearly shows how values of y are related to values
of x, it seems reasonable to start by assigning several different numbers to x
and then find the corresponding values of y to get points that lie on the graph.
We then plot these points and connect them with a smooth curve. See Figure l. Notice that the sketch doesn't show all points on the graph, but it does
establish a continuing pattern. If a sketch of the graph of an equation shows
enough of the graph so that the viewer is able to "see" the rest of the graph as
a continuation of an established pattern, we often call the sketch complete. So,
when seeking such a sketch, one approach that might be taken is to plot a
sufficient number of points so that a pattern becomes evident and then connect
the points by a smooth curve. However, it is not always clear how many points
are sufficient. Some knowledge about the given equation and what characteristics
to expect the graph of the equation to have is certainly helpful. For instance,
we know that the graph of any equation of EXAMPLE 2 Finding Intercepts  Identify the x and yintercepts for the graph given in
Figure 3.
