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Equation of spere

  • Thread starter joemama69
  • Start date
  • #1
399
0

Homework Statement


this problem has 3 parts

a- Determine an equation of the spere tha passes throught th epint 6,-2,3 and has center -1,2,1
b- Determine the curve in which this sphere intersects the yz plane
c- Determine the center and radius of the sphere x^2 + y^2 + z^2 - 8x + 2y + 6z + 1 = 0


Homework Equations





The Attempt at a Solution



a - r^2 = (6+1)^2 + (-2-2)^2 + (3-1)^2 = 69
(x+1)^2 + (y-2)^2 + (z-1)^2 = 69 is this corect

b - i dont really understand what the question is asking

c - center is (4,-1,-3)
r = (-1 + (8^2 + 2^2 + 6^2)/4)^1/2 = 5 is this correct
 

Answers and Replies

  • #2
33,162
4,847
a -- looks good
c -- looks good

For b, the y-z plane is the plane x = 0. You have the equation of the sphere, so just set x = 0 in that equation.
 
  • #3
399
0
sooooo....

1 + (y-2)2 + (z-1)2 = 69
 
  • #4
33,162
4,847
Works for me.
 
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