Write the equation of the sphere 2x2 + 2y2 + 2z2 = 8x - 24z + 1 in standard form. Find its center and radius.
Solution:
From the question it is given that 2x2 + 2y2 + 2z2 = 8x - 24z + 1
The equation of the sphere is of the form(x-a)2 + (y-b)2 +(z-c)2 = r2 , centered at (a,b,c) and with radius r.
Then, completing squares in the equation we get,
= 2(x2 - 4x + 4) + 2y2 + 2(x2 + 12x + 36) = 1 + 8 + 72
= 2(x - 2)2 + 2y2 + 2(z + 6)2 = 81
By cross multiplication we get,
= (x - 2)2 + y2 + (z + 6)2 = 81/2
So, an equation of a sphere with a center is (2, 0, -6)
And radius is √(81/2) = 9/√2
Therefore, the equation of the sphere 2x2 + 2y2 + 2z2 = 8x - 24z + 1 in standard form is (x - 2)2 + y2 + (z + 6)2 = 81/2. Center is (2, 0, -6) and radius is 9/√2.
Write the equation of the sphere 2x2 + 2y2 + 2z2= 8x - 24z + 1 in standard form. Find its center and radius.
Summary:
The equation of the sphere 2x2 + 2y2 + 2z2 = 8x - 24z + 1 in standard form is (x - 2)2 + y2 + (z + 6)2 = 81/2. Center is (2, 0, -6) and radius is 9/√2.
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