(adsbygoogle = window.adsbygoogle || []).push({}); 1. The problem statement, all variables and given/known data

Find the Equation of the sphere with points P such that the distance from P to A is twice the distance from P to B.

A(-2, 4, 2), B(4, 3, -1)

2. Relevant equations

The equation of a sphere would probably be the most relevant equation.

That is (x-h)^2 + (y-k)^2 +(z-l)^2 = r^2

3. The attempt at a solution

So the way I look at it, I figure that I have to set up an equality. Therefore d(PA) = 2d(PB). I'm assuming that since point p isn't given, it is P(x, y, z)? I don't know though. If that's the case, my equation should look something like

(x-2)^2 +(y-4)^2 +(z-2)^2 = 2((x-4)^2 +(y-3)^2 +(z+1)^2). But I'm not sure if I'm approaching the problem the right way. And I don't where to look for the radius. Any input would be appreciated! :)

**Physics Forums | Science Articles, Homework Help, Discussion**

Dismiss Notice

Join Physics Forums Today!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

# Homework Help: Multivariable Calculus~Equation of a Sphere

**Physics Forums | Science Articles, Homework Help, Discussion**