1. EQ: How do you write the equation of a circle? What does each piece in the equation represent? Demonstrated in writing in summary at conclusion of notes. Warm-Up Please log into your calculator to answer the warm- up question

2. Writing the Equation of a Circle Essential Question: How do you write the equation of a circle? What does each piece in the equation represent? Demonstrated in writing in summary at conclusion of notes.

3. EQ: How do you write the equation of a circle? What does each piece in the equation represent? Demonstrated in writing in summary at conclusion of notes. Equation of a Circle in Standard Form: (x - h) 2 + (y – k) 2 = r 2 If you are given the center and the radius, just plug in. The x-coordinate of the center is h, the y-coordinate of the center is k, and the radius is r.

4. EQ: How do you write the equation of a circle? What does each piece in the equation represent? Demonstrated in writing in summary at conclusion of notes. Example: Write the equation (in standard form) for the circle described. a) center: (-1, 3) b) center: (0, 7) radius: 3 radius: 5

5. EQ: How do you write the equation of a circle? What does each piece in the equation represent? Demonstrated in writing in summary at conclusion of notes.

6. EQ: How do you write the equation of a circle? What does each piece in the equation represent? Demonstrated in writing in summary at conclusion of notes. Example: Write the equation (in standard form) for the circle with center at (1, -2) and that contains the point (-1, 1).

7. EQ: How do you write the equation of a circle? What does each piece in the equation represent? Demonstrated in writing in summary at conclusion of notes. Example: Write the equation (in standard form) for the circle with center at (3, 6) and that contains the point (8, 1).

8. EQ: How do you write the equation of a circle? What does each piece in the equation represent? Demonstrated in writing in summary at conclusion of notes.

9. EQ: How do you write the equation of a circle? What does each piece in the equation represent? Demonstrated in writing in summary at conclusion of notes. Example: Write the equation (in standard form) of the circle that contains the points (0,2) and (4, 0).

10. EQ: How do you write the equation of a circle? What does each piece in the equation represent? Demonstrated in writing in summary at conclusion of notes. Example: Write the equation (in standard form) of the circle that contains the points (1,-1) and (-5, 7).

11. EQ: How do you write the equation of a circle? What does each piece in the equation represent? Demonstrated in writing in summary at conclusion of notes. Homework: Writing the equation of a circle worksheet problems 1 - 7

12. EQ: How do you write the equation of a circle? What does each piece in the equation represent? Demonstrated in writing in summary at conclusion of notes. Warm-Up Please log into your calculator to answer the warm- up question

13. EQ: How do you write the equation of a circle? What does each piece in the equation represent? Demonstrated in writing in summary at conclusion of notes.

14. EQ: How do you write the equation of a circle? What does each piece in the equation represent? Demonstrated in writing in summary at conclusion of notes.

15. EQ: How do you write the equation of a circle? What does each piece in the equation represent? Demonstrated in writing in summary at conclusion of notes.

16. EQ: How do you write the equation of a circle? What does each piece in the equation represent? Demonstrated in writing in summary at conclusion of notes. If you are given the equation of a circle in general form (x 2 + y 2 + cx + dy + e = 0) and asked to convert to standard form you must complete the square twice, once for the x’s and once for the y’s.

17. EQ: How do you write the equation of a circle? What does each piece in the equation represent? Demonstrated in writing in summary at conclusion of notes. Example: Convert x 2 + y 2 – 4x + 10y + 20 = 0 into standard form.

18. EQ: How do you write the equation of a circle? What does each piece in the equation represent? Demonstrated in writing in summary at conclusion of notes. Example: Convert x 2 + y 2 – 4x – 6y + 8 = 0 into standard form.

19. EQ: How do you write the equation of a circle? What does each piece in the equation represent? Demonstrated in writing in summary at conclusion of notes. Homework: Writing the equation of a circle worksheet problems 8 - 10