1. The problem statement, all variables and given/known data The direction of propagation is defined as ex=sin(theta)cos(phi), ey=sin(theta)sin(phi), ez=cos(theta). What are the values of theta and phi characterizing the direction of propagation? 2. Relevant equations We have a point in space with the coordinates (r,theta,phi)=(2,3,4) Components were defined in the problem. 3. The attempt at a solution Well, seeing as how the point is being designated by these numbers, and according to the spherical notation these numbers should represent theta and phi, I would think the answer would be theta=3 and phi=4. But that seems way too easy... so any guidance would be appreciated. Thank you in advance!