# How do I find the equation of the sphere of radius 2 centered at the origin?

##### 1 Answer

Sep 10, 2015

#### Answer:

Use Pythagoras theorem twice to derive a distance formula, hence the equation:

#### Explanation:

The distance of a point

To see this you can use Pythagoras twice:

The points

Then the points

So we can write the equation of our sphere as:

or