00:01
And this problem, we want to find the surface consisting of all points that are equidistant from the point one, sorry, 0 ,01, and the plane z equals negative 1.
00:18
So we're going to want to be reminded of how we find a, so how we find a, how we find a parabola from its, from its focus on directrix.
00:37
Because we're saying it's equidistant from a plane and a point.
00:43
So this is like the 3d version of a parabola, which is equidistant from a line and a point.
00:52
So let's suppose we're looking at a trace.
00:54
So let's look at the trace where y equals zero.
00:57
So i want to find, so here is z and here's x.
01:05
So here is my point, which is going to be the focus.
01:10
And here's my directrix, z equals negative 1.
01:21
So that we know the vertex is at here because the vertex is equidistant from the directrix and the focus by definition because the parabola is equidistant from the directrix and the focus for every point.
01:41
And so we know we have this parabola shape.
01:45
So now if we go to the standard form of the parabola.
01:49
So we have 4p z minus k is equal to x minus h squared...