1. 8-3 & 8-4: Graphing Linear Functions Mr. Gallo

2. Graphing Linear Functions  Linear Function:  The graph of this function is a ____________ _______.  Graphs of the form y = mx straight line

3. Graphing Linear Functions  Example 1: Given the point A (3, 6), find the equation of the line that passes through A and the origin. What is the slope of the line? ______________________ What could you multiply by 3 to get 6? _______________________ The equation of the line is: y = x 6 3

4. Graphing Linear Functions  Example 2-Given the point B (9, 3), find the equation of the line that passes through B and the origin. What is the slope of the line? ______________________ What could you multiply by 9 to get 3? ______________________ The equation of the line is: y = x 3 9

5. The Slope Intercept Form  The equation of line in the slope-intercept form:  represents the _________.  represents the _______________.  y-intercept is where the line crosses the y-axis slope y -intercept

6. Example 3 - Graph the equation What is the y-intercept? _______ What is the slope? ______ Example 4 - Graph the equation What is the y-intercept? ______ What is the slope? ______

7. How are the graphs alike? __________________ __________________ How are they different? _________________ _________________ They have the same slopes. They have different y –intercepts. Parallel lines

8. Example 5- Find the equation of the line with a y-intercept of 1 and a slope 3. Equation: _____________

9. Slope: _________. Example 6- Find the equation of the line passing through (0, 6) and with slope − 4. Equation: _____________ Substitute Point:

10. Example 7: Find the equation for the line passing through (3, − 4) and (9, 0). Equation: _____________ Slope: _________. Substitute Point:

11. Homework: 8.3-8.4 Worksheet