SOLUTION: 1. Find the equation of the circle with centre (0,0) and a) with a radius of 7 b) diameter of 12 c) passing through (2,-4) d) having a diameter with endpoints (5,8)

Algebra ->  Circles -> SOLUTION: 1. Find the equation of the circle with centre (0,0) and a) with a radius of 7 b) diameter of 12 c) passing through (2,-4) d) having a diameter with endpoints (5,8)       Log On


   



Question 1151351: 1. Find the equation of the circle with centre (0,0) and
a) with a radius of 7
b) diameter of 12
c) passing through (2,-4)
d) having a diameter with endpoints (5,8) and (-5,-8).
Thanks

Found 2 solutions by josgarithmetic, Alan3354:
Answer by josgarithmetic(39621) About Me  (Show Source):
You can put this solution on YOUR website!
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d) having a diameter with endpoints (5,8) and (-5,-8).
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r^2 = 5^2 + 8^2 = 89
highlight%28x%5E2%2By%5E2=89%29

Answer by Alan3354(69443) About Me  (Show Source):
You can put this solution on YOUR website!
1. Find the equation of the circle with centre (0,0) and
a) with a radius of 7
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A circle's equation is (x-h)^2 + (y-k)^2 = r^2
(h,k) is the Origin ---> h = k = 0
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x%5E2+%2B+y%5E2+=+7%5E2
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b) diameter of 12
r = 6, same as a
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c) passing through (2,-4)
r^2 = 2^2 + 4^2 = 20
same as a