00:04
So here we would like to find the equation for a sphere centered at 5, 4, 9, whose interior is entirely in the first octant.
00:14
And we'd like to find one with the largest radius as possible.
00:19
Well, to write the equation for a sphere, you need two things.
00:22
You need to know the coordinates of the center, which we have.
00:27
And you need to know the radius, which we can find from the requirements that we were given.
00:35
So we need to figure out how close this is.
00:38
To any one of the coordinate axes so that we can make the radius as large as possible.
00:45
With the next coordinate of five, we know that the sphere, the center of the sphere, is five units in front of the yz plane...