1. The problem statement, all variables and given/known data The x and y coordinate direction angles of a vector are 50 and 105 degrees, respectively. If the z component of the vector points in the negative z direction, what is the z coordinate direction angle? 2. Relevant equations 3. The attempt at a solution I was going to try using cos^-1(z comp/magnitude) but since I'm not given a specific vector, that wouldn't work.. Can someone kind of explain how to go about solving this? I feel like it's easy and I'm making it complicated. Much appreciated!