Find the center and radius of the sphere x2 + y2 + z2 - 6y + 8z = 0.
Solution:
We have equation of the sphere centred at (h, k. l) and having radius r is given by
(x - h)2 + (y - k)2 + (z - l)2 = r2---------------------------(1)
To identify the centre and radius of the given sphere we have to convert the given equation
x2 + y2 + z2 - 6y + 8z = 0 to the form in equation (1)
Now group the x , y and z terms and by completing the square, we get
x2 + (y2 - 6y + 9) +(z2 + 8z + 16) = 9 + 16
(x - 0)2 + (y - 3)2 + (z + 4)2 = 52
Hence centre of the sphere is (0, 3, -4) and radius = 5
Find the center and radius of the sphere x2 + y2 + z2 - 6y + 8z = 0.
Summary:
The center and the radius of the sphere with the equation, x2 + y2 + z2 - 6y + 8z = 0 are (0, 3, -4) and 5 respectively.
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