# Equation representing the set of all points

• May 3rd 2009, 09:29 AM
Murphie
Equation representing the set of all points
Im confused on how to do this particular problem:

Find the equation representing the set of all points (x,y,z) whose distance from the point( 1,5,-4) is 12.

I'm pretty sure I need to use the distance formula, just don't really know where or how.

Some help with this would be great!
Thanks!
• May 3rd 2009, 10:26 AM
skeeter
Quote:

Originally Posted by Murphie
Im confused on how to do this particular problem:

Find the equation representing the set of all points (x,y,z) whose distance from the point( 1,5,-4) is 12.

I'm pretty sure I need to use the distance formula, just don't really know where or how.

Some help with this would be great!
Thanks!

the set of points described is a sphere of radius 12 centered at (1,5,-4) ...

$(x-1)^2 + (y-5)^2 + (z+4)^2 = 12^2$