1. The problem statement, all variables and given/known data Write the vectors B,D, and F in the figure in Cartesian form, with unit vectors. (See attachments) 2. Relevant equations ax = a cos theta ay = a sin theta where a = magnitude of vector a, and theta = the angle vector a makes with the positive direction of the x axis 3. The attempt at a solution I'm having trouble with this "the angle vector a makes with the positive direction of the x axis" business. What does that mean, exactly? The smallest angle that the vector can make with the positive direction of the x axis? Because there are two angles it could make, technically. My book is not specific and I'm confused. In one part of my book it has a note: "Angles that are measured relative to the positive direction of the x axis are positive if they are measured in the counter clockwise direction and negative if measured clockwise. For example, 210 degrees and -150 degrees are the same angle" I thought maybe it's just talking about a protractor but then I wondered if it had anything to do with the angle theta business. So how exactly does one find the angle a vector makes with the positive direction of the x axis? The thetas I found for the vectors in the images are: Vector B: 53 degrees Vector D: 143 degrees Vector F: I haven't any idea For Vector B, I arbitrarily decided to use the smaller angle. For Vector D, I stuck with the smaller angle idea and found theta to be 143 degrees. For Vector F, I'm puzzled by the addition of the z axis, as our book doesn't have a formula for resolving the vector of a three dimensional vector, or at least we haven't covered it and I haven't found it. I also wonder how I'm supposed to interpret the "the angle the vector makes with the positive direction of the x axis" business on a three dimensional coordinate system.