1. Section 1.5
Circles
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2. A circle is a set of points that are a fixed distance called the radius (r) from a point called the center (h, k)
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5. Write the standard form of the equation of the circle with radius 4 and center (2, –4).
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6. #9) Find the center, radius, and standard form of the equation.
Practice:
#9) Find the center, radius, and standard form of the equation.
(1,2) (4,2)
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7. Copyright © 2013 Pearson Education, Inc. All rights reserved

8. Copyright © 2013 Pearson Education, Inc. All rights reserved

9. Copyright © 2013 Pearson Education, Inc. All rights reserved

10. Changing from standard form to general form:
(x + 2)2 + (y – 3)2 = 5
(x + 2) (x + 2) + (y – 3) (y – 3) = 5
x2 + 4x y2 – 6y + 9 = 5
x2 + 4x + y2 – 6y + 8 = 0
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11. Copyright © 2013 Pearson Education, Inc. All rights reserved

12. Practice:
Find the center, radius, the intercepts and graph.
# 25) x2 + y2 – 2x – 4y – 4 = 0