Find the Area (polar)

Question

Find the area that is outside r = 2 but inside r = 4 cos θ.

Type your answer in the space below and give 3 decimal places. If your answer is less than 1, place a leading "0" before the decimal point (ex: 0.482).

Answer 1

Hi Erika,

First you will need to graph

r= 4 cos θ.  This can be done by graphing y = 4 cosθ and then "wrapping the graph about the origin".  This method takes some practice but helps make the problem more transparent.  However you can also use a graphing calculator.  The graph for r= 2 should be easy by comparison.  Then you should shade in the are you are trying to find. This will allow you to find the upper and load limit more easily.