Get in Line!

Lesson Plan - Get It!

Audio:

• Am I making enough profit?
• Are my sales increasing or decreasing?

We can track all that on a graph! Let's first start with plotting points.

To plot the point (3,2), we will count three to the right (in red) and two up (in green):

Here is another one. Let's graph the point (-2, 4). In this case, we will count two to the left (in red), and then 4 up (in green):

• Are you ready to get a little more into graphing?

Let's graph a line!

First, we need to know that in the linear function y = mx + b, the m value represents the slope, and the b value represents the y-intercept.

We will start with the line y = ²/₃x - 4.

The slope is ²/₃, and the y-intercept is -4:

We start at the y-intercept (in this case, -4). Plot a point on the y-axis at -4. This is where the line for this function intercepts, or crosses, the y-axis:

Now, we count the slope from the y-intercept.

The slope, which is represented by m, measures the steepness of the line. The steepness is the rise over the run from a certain point to the next point.

In this function, the slope, or m value, is ²/₃ which means from the y-intercept, the line will rise by 2 and run to the right by 3. Plot another point here, which is (3,-2):

Now draw a line through the two points!

Now, that you know how to graph a line, let's go to the Got It? section!