Im doing this question: express this in trigonometric form 3-3i. So I found out the "r" which is 3 sqrt 2
then I did arctan -3/3= which gave me an angle of -45. Why is it NEGATIVE? Also, apparently -45 is the same thing as 7pi/4. How are they the same?????? I don't see that anywhere on the unit circle!!!! where does 7 come from and where does pi/4 come from too????
