2. Equations of Lines

3.  The slope intercept for of the equation of a line with slope m and y-intercept b is y=mx+b. In an applied context, m is the rate of change and b is the intial value (when x=0)

4.  The equation of the line with slope m that passes through a known point (x 1,y 1 ) is y-y 1 = m(x-x 1 )

5.  A) Is the rate of change of the Blood Alcohol percent a constant? What is it?  B) Write the equation of the function that models the blood alcohol percent as a function of the number of drinks.

6.  Use two points to find slope.  Use point slope form with one of the points.

7.  The number of people (in millions) in US prisons or jails grew at a constant rate from 1990 to 2000, with 1.15 million people incarcerated in 1990 and 1.91 million incarcerated in 2000.  A) What is the rate of growth of people incarcerated from 1990 to 2000?  B) Write a linear equation that models the number N prisoners as a function of the year x  C) The Bureau of Justice Statistics projected that 2.29 million people would be incarcerated in 2005. Does your model agree with this projection?

8.  Horizontal lines have a slope of 0.  When two points of a horizontal line are given the y values are the same.  When writing an equation for a horizontal line, it should be written as y=a

9.  Vertical lines have an undefined slope.  When two points of a vertical line are given the x values are the same.  When writing an equation for a vertical line, it should be written as x=a.

10.  Two lines are considered to be parallel if they have the exact same slope.  Use point slope form to find equation given a point and a parallel line.

11.  Two lines are considered to be perpendicular if they have slopes that are opposite reciprocals.  Use point slope form to find equation given point and perpendicular line.

12.  Ax + By = C  A,B, and C are real numbers, with A and B not both equal to 0.

14.  Example 8 on page 67

16.  Example 9 on page 68

17.  Pages 70-74  1,3,7-9,11,15,25,27,33,35,37,43,49,53

18.  Pages 80-83  1-42