The tutor introduces another way of stating a point location.

Back in my Oct 29 post I described angles in standard position and reference angles with a couple of illustrations. The idea relates to polar coordinates.

With (x,y) coordinates, which are known as rectangular coordinates, the location is indicated by (across, up or down). With polar coordinates, it’s related by (distance from (0,0), angle in standard position).

Example 1: Show the location (-20,9) in polar coordinates.

Solution: From the illustration below, see that (-20,9) is 21.9, 155.8° in polar coordinates.

In a coming post I’ll show how to convert from rectangular to polar coordinates:)

Source:

Larson, Roland E. and Robert P. Hostetler. Calculus. Toronto: DC Heath and Company,
   1989.

Jack of Oracle Tutoring by Jack and Diane, Campbell River, BC.