Hi everyone! Read through the material below, watch the videos, and follow up with your instructor if you have questions.

Lesson 2: Lines and Functions

Topic. This lesson covers Session 2: Lines and Functions

Learning Outcomes.

• Review basic properties of lines.
• Develop a conceptual understanding of functions.

WeBWorK. There is one WeBWorK assignment on today’s material:

1. Lines Review

Question of the Day: What is the meaning of the “slope” of a line?

## Lines, slope and intercepts

In this section, we review a topic you have seen before: lines. We will work through some examples below, but if you have questions or need help with any of the ideas about lines I highly recommend taking a look at these additional video resources. For example: what is the slope? What are the intercepts (x- and y-)? How do I find them? What is the slope-intercept form of a line? What is the point-slope form of a line?

Important facts about lines

• The slope of a line passing through two points and is • A line with slope that passes through the point will have equation: called the point-slope form of the line.
• The x-intercept of a line is the point where the line crosses the x-axis.
• The y-intercept of a line is the point where the line crosses the y-axis.
• A line with slope and -intercept will have equation: called the slope-intercept form of the line.
• If two lines are parallel, their slopes are equal • If two lines are perpendicular, their slopes are negative reciprocals: Example 1.

• Find an equation of the line passing through the points and • Find the slope, y-intercept, and graph VIDEO: Example 1 – Equations of lines

Video by Irania Vazquez

## What is a function?

Every once in a while you run into an idea in math that is so big, and so basic… One of these ideas was numbers (you ran into this one at a very young age). Another of these ideas is functions. In later lessons, you will be learning a lot technicalities about functions – but for today, we really want you just to understand the big idea. What is a function?

This presentation gives an introduction:

And this video provides an introduction along with several examples

VIDEO: Introduction to Functions

Video by Irania Vazquez

#### Exit Question

Find the equation of the line in the graph below in slope-intercept form. 