Double Integral One Loop of the Rose

1. Mar 19, 2013

. Arctic.

1. The problem statement, all variables and given/known data

Use a double integral to find the area of one loop of the rose r = cos 3$\theta$

2. Relevant equations

3. The attempt at a solution

This is a past test question. The only thing I got wrong was the set up while I got the rest of the mechanical steps right. I set up as

∫∫ (r*cos 3θ) dr dθ

which is not right. I thought it might either be

∫∫ (r*r) dr dθ

or

∫∫ (cos 3θ * cos 3θ) dr dθ

2. Mar 19, 2013

SteamKing

Staff Emeritus
Hint: r = cos theta, emphasis on equal