Rings and more rings.
Geometry
Level
2
determine the maximum value for K (integer) for the equation to represent a circumference
The answer is 4.
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1 solution
By completing the square, the equation can be written (x-1)^2 + (y+2)^2 = 5-k. For this to be a circle, we need 5-k > 0, or k < 5. The largest integer for which this holds is k = 4.