Circles An Introduction

1
Circles An Introduction

• SPI 3103.3.11    Graph conic sections (circles,
  parabolas, ellipses and hyperbolas) and
  understand the relationship between the standard
  form and the key characteristics of the graph.

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• The general form for the equation of a circle is
  (x h)2 (y k)2 r2.
• The center of the circle is the ordered pair (h,
  k).
• The radius of the circle is r.

3

• For each of the following problems, find the
  center and radius.
• 1. (x 3)2 (y 4)2 25

4

• 2. (x 1)2 y2 44
• 3. (x 8)2 (y 2)2 7

5

• 4. x2 y2 18
• 5. (x 7)2 (y 2)2 0
• 6. x2 (y 4)2 44

6

• Write an equation for the circle with the given
  center and radius.
• 7. Center (2, 7), radius 4

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• 8. C (0, 2), r 6
• 9. C (0, 0), r

8

• Write each equation in the form (x h)2
  (y k)2 r2.
• 10. x2 y2 10x 6y 13 0

9

• 11. x2 y2 4x 14y 17 0
• 12. x2 y2 20x 247 0