Mar 23, 2009 #1 L loveinharovrd Newbie level 4 Joined Oct 26, 2008 Messages 6 Helped 0 Reputation 0 Reaction score 0 Trophy points 1,281 Activity points 1,310 (px-y)(py+x)=2p where p=y' (Hint:let z=y^2) answer: (c^2+2c)x^3-xy^2(2c+4)-4cx=0