Cover-Kurve
Ha 2016

k = 4
a = 0.1 (slider from -5 to 5, step 0.1)
b: ((x^(2) + y^(2)) * (((-(x^(2) + (4 * y))^(2)) * (k^(2) - x^(2) - y^(2))) + ((16 * a^(2)) * (x^(2) + y^(2))) + ((8 * a) * ((k^(2) * x^(2)) + ((x^(2) + (4 * y)) * (x^(2) + y^(2))))))) = ((k^(2) * x^(4)) * ((-k^(2)) + x^(2) + y^(2)))