1. The slope-intercept form of a line: y = mx + b

2. Graph the following family of lines using the graphing calculator: 1.y = 3x + 2 2.y = 5x + 2 3.y = -4 x + 2 4.y = 1/2 x + 2 All of these equations are written in y = mx+b form. What does m represent in each equation? Check your hypothesis by using the table feature of the calculator.

3. Graph the following family of lines using the graphing calculator: 1.y = 3x + 2 2.y = 3x - 4 3.y = 3x 4.y = 3 x + 8 All of these equations are written in y = mx+b form. What does b represent in each equation? Check your hypothesis by using the table feature of the calculator.

4. Given y = mx + b  m represents the slope of the line  b represents the y-intercept -- the point where the line intercepts or crosses the y-axis.

5. Graphing lines in the form y = mx + b is very easy since you know one point, the y-intercept, and the slope. Graph each of the following: 1.y = 2x + 5 2.y = - x – 3 3.y = 4x 4.y = - 2

6. Finding the equations of lines is very easy if you know the y-intercept and slope. Find the equation of the line: 1.t hat passes through the origin with slope – 2. 2.w ith y–intercept of 4 and slope 2/3. 3.t hat is horizontal and passes through the point ( 2, 5)

7. What if the equation is not given in y = mx + b form? Graph the equation whose standard form is 3x + 2y = 6.  Strategy 1: Rewrite the equation in y = mx + b form.  Strategy 2: Find the x-intercept and the y- intercept.

8. To find the x-intercept and the y-intercept of a line written in standard form:  Let x = 0 to find the y-intercept.  Let y = 0 to find the x-intercept.  Example: Find the x-intercept and the y- intercept of the line 3x – 5y = 15. Then graph the line.

9. Graphing equations in different forms:  Point-slope form: y – y 1 = m(x – x 1 ) Use a point (x 1, y 1 ) and the slope, m.  Standard form Ax + By = C  Rewrite in y = mx + b form OR  Find the x-intercept and the y-intercept OR  Make a table of solutions.  Slope-intercept form y = mx + b Use the y-intercept and the slope.

10. Assignment:  6.4 #19-45 odds Due Wednesday 1/14/04  6.5 #13-25 all. Use graph paper. Write the equation next to each graph. Due Thursday 1/15/05