Section 2.2
Circles
Example 1: Find the center -radius form of the equation of each circle described.
a) center at (−3, 4), radius 6
b) center at (0, 0), radius 3
c) diameter with endpoints (−1, 2) and (11, 7).
Section 2.2 Circles
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Example 2: Graph the following equations.
a) (𝑥 − 1)2 + 𝑦 2 = 1
b) 𝑥 2 + 𝑦 2 = 4
Example 3: Show that 𝑥 2 − 6𝑥 + 𝑦 2 + 10𝑦 + 25 = 0 has a circle as its graph. Find the center
and radius.
Section 2.2 Circles
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Example 4: Show that 2𝑥 2 + 2𝑦 2 − 6𝑥 + 10𝑦 = 1 has a circle as its graph. Find the center
and radius.
Example 5: The graph of the equation 𝑥 2 + 10𝑥 + 𝑦 2 − 4𝑦 + 33 = 0 either is a point or is
nonexistent. Which is it?
Section 2.2 Circles
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