If y^2 + 18x^2 = 18x – 3y, what is dy/dx at the point where x = 1. Posted on May 5, 2017 If y^2 + 18x^2 = 18x – 3y, what is dy/dx at the point where x = 1. If y^2 + 18x^2 = 18x – 3y, what is dy/dx at the point where x = 1.