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Math Help - Find an equation of the largest sphere with center...

  1. #1
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    Find an equation of the largest sphere with center...

    Find an equation of the largest sphere with center (11, 19 , 12) that is contained completely in the first octant.

    Need help solving... thank you!
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  2. #2
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    Quote Originally Posted by thomann061 View Post
    Find an equation of the largest sphere with center (11, 19 , 12) that is contained completely in the first octant.

    Need help solving... thank you!
    The coordinates give you the answer.
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    yes i know, i am confused about how to find the radius.
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    Quote Originally Posted by thomann061 View Post
    yes i know, i am confused about how to find the radius.
    Have you plotted the center on a graph? If the radius is 19, is it possible for it not to exceed the 1st octant? What about 12?
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  5. #5
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    yes i have graphed it. i came up with this as an answer so far: (x-11)^2 + (y-19)^2 + (z-12)^2 = 0. i dont know what you mean by if the radius is 19? i thought it would be around 2 or 4.
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    Quote Originally Posted by thomann061 View Post
    yes i have graphed it. i came up with this as an answer so far: (x-11)^2 + (y-19)^2 + (z-12)^2 = 0. i dont know what you mean by if the radius is 19? i thought it would be around 2 or 4.
    You think a radius of 2 or 4 is the largest sphere you can fit in the first octant?

    Also, your equation is of a point.
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    as you can tell i am very confused... i just can't seem to understand how to solve this or think about it visually. could you show me how to solve for it?
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    Quote Originally Posted by thomann061 View Post
    as you can tell i am very confused... i just can't seem to understand how to solve this or think about it visually. could you show me how to solve for it?
    Draw a picture a find the center.
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    i found the center, i still cant tell how to find the radius
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    Quote Originally Posted by thomann061 View Post
    i found the center, i still cant tell how to find the radius
    If you found the center, how far can you move away from it before you hit an axis: x, y, or z?
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  11. #11
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    i mean 12 from the y axis
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  12. #12
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    Quote Originally Posted by thomann061 View Post
    i mean 12 from the y axis
    So if you move 12 units, you won't cross the x-axis?
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  13. #13
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    ha i mean 19 from the x axis
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  14. #14
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    Quote Originally Posted by thomann061 View Post
    ha i mean 19 from the x axis
    Here is a sphere of 8 and 19. You tell me.



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  15. #15
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    ohhhh okay its 11^2 for the radius
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