00:01
All right, so let's say earth has a radius of 3 ,963 miles.
00:07
So the equation that governs the surface of earth is going to be like x squared plus y squared plus z squared is equal to r squared, so 3963 squared.
00:22
You know, we'll just, we'll leave it symbolically as 3963 miles squared.
00:29
So that would be our equation.
00:31
Our lines of longitude that run north -south could be represented.
00:37
And if we draw our sphere and we have our angle, we'll call this theta, like your line of longitude, then the radius of this little circle that is being drawn is going to be r times the radius of earth is this distance, right? or this leg of the triangle, i should say.
01:00
It's r cosine theta.
01:03
So we can define if this is our x coordinate right here, this is our z coordinate right here, and then our y coordinate is going this way...