00:01
This question asks us to transform these rectangular coordinates into spherical coordinates.
00:05
To do that, we need to know a few equations.
00:09
Our first equation is that x is equal to row sine phi, cosine theta, y is equal to row sine phi, sine theta, z is equal to row cosine phi, and row squared is equal to x squared plus y squared plus z squared.
00:38
Since we know what x, y, and z are, we're able to start with the row squared equation, and we're able to plug that in to solve for row.
00:46
So let's do that.
00:47
We get that row squared is equal to zero squared plus negative two squared plus z squared plus z squared plus z squared.
00:54
0 squared.
00:56
And if we solve for row, we get that row squared is equal to 4, which just means that row is equal to 2.
01:04
Great.
01:05
Now we can plug it into the z equation because now all that's missing is our 5.
01:10
So z is 0, which is equal to 2, cosine of phi.
01:16
Now we must remember that phi is in between 0 and pi.
01:22
So we need to find where cosine is 0.
01:25
What you can plug in to make cosine 0 between 0 and pi.
01:30
The one number that satisfies this is when phi is equal to pi over 2.
01:38
So that means phi is pi over 2.
01:40
So then we can take all this and we either plug it into our x or y equation.
01:45
But we have to remember that whichever one we choose, we must make sure that it is true for the other.
01:51
So let's say if i were to choose x, i would need to make sure to plug it back in and make sure it was true for the y.
01:55
But on this case i'm going to choose y.
01:59
And so my y is negative 2 is equal to 2, sine of pi over 2, sine of theta.
02:09
So now i'm just going to solve for my theta.
02:13
So to start, i'm going to divide both sides by 2, so we get negative 1 is equal, and sine of pi over 2 is just 1.
02:20
So it's equal to 1, sine theta.
02:25
So when is sine of theta equal to negative 1? well, we know that theta is between 0 and 2 pi...