Write the equation of the sphere in standard form.
2x2 + 2y2 + 2z2 = 12x - 24z + 1
Solution:
The standard equation of a sphere is (x - a)2 + (x - b)2 + (x - c)2 = r2
Where a, b, c is the centre and r is the radius
Given: 2x2 + 2y2 + 2z2 = 12x - 24z + 1
It can be written as
2x2 + 2y2 + 2z2 - 12x + 24z - 1 = 0
By combining the x, y and z terms
(2x2 - 12x) + 2y2 + (2z2 + 16z) = 1
Divide the entire equation by 2
(x2 - 6x) + y2 + (z2 + 8z) = 1/2
Now complete the square for x by adding 9 on both sides
Complete the square for z by adding 16 on both sides
(x2 - 6x + 9) + y2 + (z2 - 8z + 16) = 1/2 + 9 + 16
(x - 3)2 + y2 + (z - 4)2 = 25½
Therefore, the equation of the sphere in standard form is (x - 3)2 + y2 + (z - 4)2 = 25½.
Write the equation of the sphere in standard form.
2x2 + 2y2 + 2z2 = 12x − 24z + 1
Summary:
The standard form of the sphere 2x2 + 2y2 + 2z2 = 12x - 24z + 1 is (x - 3)2 + y2 + (z - 4)2 = 25½.
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