The point (4, -4) lies in Quadrant IV. Since we are interested only in positive angles, we choose 315 degrees with a radius (magnitude) of 4√2. That automatically eliminates Answer Choices A, B and C, so all we have to do now is to verify that (-4√2, 135 degrees) also represents (4, -4). It does: Going to Quadrant II with angle 135 degrees, and then using -4√2 as the magnitude, takes us to Quadrant IV.
Answer: Reflection is the change in direction of a wavefront between two different media so that the wavefront returns into the medium from which it originated.
