1. The problem statement, all variables and given/known data Example: Problem 5.33 Show that the magnetic field of a dipole can be written in the following coordinate free form: 2. Relevant equations [URL]http://teacher.pas.rochester.edu/PHY217/LectureNotes/Chapter5/LectureNotesChapter5138.jpg[/URL] [URL]http://teacher.pas.rochester.edu/PHY217/LectureNotes/Chapter5/LectureNotesChapter5140.jpg[/URL] 3. The attempt at a solution [URL]http://teacher.pas.rochester.edu/PHY217/LectureNotes/Chapter5/LectureNotesChapter5141.jpg[/URL] Okay, I'm stumped on the last step. I can see on the one before it that (m.r) is added and subtracted to keep it even, but how do the two negative terms (r-hat and theta-hat) equate to -m? If I use the trig terms, pull out the m, use a random angle and add them together, I don't get -1.