00:01
In this problem, we want to show that in cylindrical coordinates, planes that are perpendicular to the x -axis have equations in the form of r equal to a times the secant of theta, where a is some constant, and that planes perpendicular to the y -axis have equations in the form of r equal to b times the cosecant theta, where b is some constant.
00:25
So first, recall how do we utilize cylindrical coordinates.
00:35
So in cylindrical coordinates, the x -coordinate is defined as some radius r times the cose of theta.
00:46
Y is defined as r times the sine of theta, and z remains z.
00:56
This is how our cartesian coordinates are related to our polar coordinates.
01:04
So now let's look at what happens when we have planes that are perpendicular to the x -axis.
01:21
This is easier to visualize if you were to draw a sketch.
01:33
So a plane perpendicular to the x -axis will be within the yz plane.
01:42
So a plane like so.
01:48
And so we notice the equation of such a plane will be in the form of x equal to some constant a.
02:03
So in this case, let's say our plane is located at x equal to a.
02:12
And now using our conversions into cylindrical coordinates, we have that x is equal to r cos theta...