1. The problem statement, all variables and given/known data Transform the coordinates from the red c-system to the blue system. (Picture) 2. Relevant equations Using(X Y) for the red cartesian system and (x y) for the blue system 3. The attempt at a solution The solution to this problem gives x=Xcos▼ + Ysin▼ y=-Xsin▼+Ycos▼ Im not sure i understand in what way was this transformed. How can x coordinate in blue system contain Y coordinate from red system?