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Graphs Of Circles |
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Lesson 1 |
Problem: Write the equation of a circle that has a center at (-2, 4) and a radius of 2?
Solution The equation of a Circle is: (x - h)2 + (y - k)2 = r2;
Step 1: where coordinate of the center of the circle is (h, k) and r is radius.
Solution The equation of given circle is [x - (-2)] 2 + (y - 4)2 = (2)2;
Step 2:
Solution (x +2)2 + (y - 4)2 = 4
Step 3:
Solution The answer is: (x +2)2 + (y - 4)2 = 4
Step 4:
Complete
Try two practice problems:
Do the following:
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A. |
Write the equation of a circle whose diameter is 16 and whose center is at (2, 8)? |
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B. |
What are the coordinates of the center of this circle? (x + 5)2 + (y - 7)2 = 25. |