SOLUTION: Find the equation, in standard form, of the circle. x-intercepts -3 and 15, y-intercepts -5 and 9

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Question 1183682: Find the equation, in standard form, of the circle.
x-intercepts -3 and 15, y-intercepts -5 and 9
Answer by ikleyn(52898) About Me  (Show Source):
You can put this solution on YOUR website!
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Due to symmetry, x-coordinate of the center is half way between the x-intercepts, i.e. %28-3%2B15%29%2F2 = 12%2F2 = 6.


Due to the same reason,  y-coordinate of the center is half way between the y-intercepts, i.e. %28-5%2B9%29%2F2 = 4%2F2 = 2.


So, the center is the point  (6,2).



Now calculate the distance  " r "  from the center to any one of the four given intercept points, using the distance formula.



Then the standard equation of the circle will be


    %28x-6%29%5E2 + %28y-2%29%5E2 = r%5E2.

You got all necessary instructions.