Coordinates

The angle between two sets of Cartesian coordinates, (x,y) and (x',y'), is \phi.
1. Find the relations between the unit vectors of (x',y') in terms of the unit vectors of (x,y).
2. For an arbitrary vector \vec{A} with components (A_x,A_y) in the (x,y) set, find its components, (A_{x'},A_{y'}), in the (x',y') set.