__Activity 2. - The x coefficient or “m” in y = mx + b:Understanding its use.__

Use the StraightLineEqn.xls tool, which displays a graph ofan equation of the form:

y = mx + b.

Do This:

Using the tool, first change the value of the constant termrepresented by “b” to 0. Then change the x coefficient and note and discuss thechanges in each graph. NOTE: To complete a change press the enter key aftertyping the new value.

Here are some examples. Below each equation note thedifference in the graph.

CLUSTER #1:

y = 2x

y = 4x

y = 6x

You may try some of your own. When you get the connection, proceed.

Here are some more examples. Below each equation note thedifference in the graph.

CLUSTER #2:

y = -2x

y = -4x

y = -6x

You may try some of your own. When you get the connection, proceed.

Answer these questions:

(a)

(b)

(c)

(d)

TEACHER NOTES

This lesson incorporates the following teaching strategiesbases on the NCTM standards.

- Technology integration
- Interactive learning
- Concept-building through discovery
- Actively building new knowledge from experience and prior knowledge
- Discourse in mathematics
- Formulate explanations
- Mathematical literacy
- Using modeling to solve problems
- Making connections by investigating various models

In addition the lesson meets the following technologyguidelines specified by

- Applying technology to meaningful problems
- Employing technology to improve pedagogy
- Connect mathematical topics
- Use multiple representations