1. 2.2 Parallel and Perpendicular Lines and Circles Slopes and Parallel Lines • If two nonvertical lines are parallel, then they have the same slopes. • If two distinct nonvertical lines have the same slope, then they are parallel. • Two distinct vertical lines, with undefined slopes, are parallel.

2. Example 1: Writing Equation of a Line Parallel to a Given Line

3. Solution X1=-2 Y1=-7

4. What is the slope of the line? Given equation Slope of the line is –5.

5. X1=-2, y1=-7, and m=-5

6. Practice Exercise

7. Answer to the Practice Exercise

8. Slopes and Perpendicular Lines • If two nonvertical lines are perpendicular, then the product of their slopes is –1. • If the product of the slopes of two lines is –1, then lines are perpendicular. • A horizontal line having zero slope is perpendicular to a vertical line having undefined slope.

9. Example 2: Finding the Slope of a Line Perpendicular to a

10. Solution Solve the given equation for y. Slope is –3/2.

11. Given line has slope –3/2.

12. Practice Exercise

13. Answers

14. Definition of a Circle A circle is the set of all points in a plane that are equidistant from a fixed point called the center. The fixed distance from the circle’s center to any point on the circle is called the radius.

15. The Standard Form of the Equation of a Circle Center Any point on the circle

16. Example 3 Finding the Standard Form of a Circle’s Equation

17. Solution

18. Practice Exercises

19. Answers

20. Example 4: Using the Standard Form of a Circle’s

21. Solution

22. Practice Exercise

23. Answer

24. The General Form of the Equation of a Circle

25. Example 5: Converting the General Form of Circle’s

26. Solution

27. r=2 h=-4 k=-2

29. Practice Exercise

30. Answer