The Attempt at a Solution
-In order for me to figure out this problem I had to reverse the equality to isolate the Ө on the left side making the new equation 9cos(3Ө)=r^2. The first thing I’m going to do is change cos(3Ө) in terms of cos and sin. That will make my new equation 9(2cos^3Ө – cosӨ – 2sin^2ӨcosӨ) = r^2. Now since r^2 will just reduce to x^2 + y^2 I am now left with the equation 9(2cos^3Ө – cosӨ – 2sin^2ӨcosӨ) = x^2 + y^2. After this I have no idea what comes next.