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Old January 12th, 2009, 09:05 AM
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Default Equation of Largest Sphere

Find an equation of the largest sphere with center (5,4,9) that is contained in the first octant?

I really have no clue as to how to set this problem up. I do know the equation for a circle is: (x-h)^2+(y-k)^2+(z-l)^2=r^2

If I substitute these points into the equation I get

(x-5)^2+(y-4)^2+(z-9)^2=r^2

This is as far as I can get. I appreciate the help.
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Old January 12th, 2009, 09:10 AM
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4 \geq r Since the sphere center is at (5,4,9) Otherwise it would go to the negative y axis.
r^2 =16
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Old January 12th, 2009, 09:14 AM
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Default RE:

So what would the equation be?

(x-5)^2+(y-4)^2+(z-9)^2=16

???
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Old January 12th, 2009, 09:15 AM
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Yes
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