SOLUTION: find the center-radius form of the equation of a circle with center (4,8) and tangent to the X-axis.

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Question 461758: find the center-radius form of the equation of a circle with center (4,8) and tangent to the X-axis.
Answer by Gogonati(855) About Me  (Show Source):
You can put this solution on YOUR website!
The standard form of the equation of the circle is %28x-h%29%5E2%2B%28y-k%29%5E2=r%5E2
Since our circle is tangent to the x-axis its radius will be perpendicular to the
the x-axis at the point (4, 0), and its radius will be:
r%5E2=%284-4%29%5E2%2B%280-8%29%5E2=64, and the equation of the circle is:
%28x-4%29%5E2%2B%28y-8%29%5E2=64.