2. Algebra 2 3.7

3. Parallel lines have the same ___________ but different _______________. slope y-intercepts Determine whether the graphs of each pair of equations are parallel. yes no

4. No, these are the same line Write an equation that contains a given point and is parallel to a given line. Example 1: (-1, 3) Step 1: Find the slope of the given line by solving for y: Step 2: The new line has the same slope as the given equation, so we use that slope. Also, use the point-slope form of a linear equation:

5. (-1, 3)m = -2 Step 3: Solve for y (change it to slope-intercept form)

6. Example 2: (-2, -4)

7. The slopes of perpendicular ( ) lines are negative reciprocals. What is the negative reciprocal of ? Of ? Determine whether the graphs of each pair of equations are perpendicular: YES

8. Determine whether the graphs of each pair of equations are perpendicular: NO

9. Example 1: Write an equation of the line perpendicular to and containing the point (2, -3). Step 1: Find the slope of the given line by solving for y. Step 2: Find the negative reciprocal of that slope. Step 3: Substitute the given point (2, -3) and that slope in the point-slope formula.

10. Step 4: Solve for y (put in slope-intercept form)

11. Write an equation of the line perpendicular to the given equation and containing the given point: Example 1: (-1,2) It’s already solved for y. The negative reciprocal of the slope is Use your calculator

12. Write an equation of the line perpendicular to the given equation and containing the given point: Example 1: (3, 4) The negative reciprocal of the slope is Use your calculator

13. Classwork: 2, 8, 14, 18/141

14. Get ready for a “Small Quiz” to be written on your grade sheet.

15. THE END

16. Quiz. Copy the problems and write the answer. Put your grade paper on the front of your row, quiz side down. 1. Graph: 2. Write the equation of the line between (-2,3) and (5,8). Solve for y.