https://web2.0calc.com/questions/what-is-the-polar-form-of-the-equation-of-x-6-2-y-2-36
Unfortunately, I haven't learned this yet. However, I believe this site will help you:
http://mathforum.org/dr.math/faq/formulas/faq.polar.html
See my answer at: https://web2.0calc.com/questions/what-is-the-polar-form-of-the-equation-of-x-6-2-y-2-36#r2