SOLUTION: Explain why the graph of x2 + y2 - 4x + 2y + 5 = 0 is a single point.

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Question 548247: Explain why the graph of x2 + y2 - 4x + 2y + 5 = 0 is a single point.
Answer by solver91311(24713) About Me  (Show Source):
You can put this solution on YOUR website!


Because it is a circle with a radius of zero.



Complete the square on both and to put the equation into



form, which is a circle centered at with radius

Rearrange:



Divide the coefficient on the 1st degree term by 2, square the result, and add that result to both sides. Do the same thing with the coefficient on the 1st degree term.



Factor the two perfect square trinomials and collect terms:



Which is a circle centered at with radius

John

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