Rectangular & Polar Coordinates

This applet allows you to move around a point to find the rectangular coordinates and the polar coordinates.

After playing around with the applet, consider these questions: 1: How can you convert from rectangular coordinates to polar coordinates? Come up with some sort of formula to use. 2: What are the major differences in rectangular coordinates versus polar coordinates? Think of at least two. 3: Why would rectangular coordinates be more useful than polar coordinates and vice versa? Think of specific examples.