Polar Coordinates

Question

Find Cartesian coordinates of polar point (-1,3pi/4).  

Answer 1

Make a little drawing, showing movement in NEGATIVE 45^o direction (thru quadrant IV) going a total distance 1 from origin.  (This is equivalent to going -1 'distance' associated with direction 135^o)

 

Do you then locate the endpoint as (-1/√2,-1/√2).  Of course, some people might want you to rationalize denominators.