y=ax^2+bx+c

a = 1 (slider from -4 to 4, step 0.5)
b = 1 (slider from -4 to 4, step 0.5)
c = 1 (slider from -4 to 4, step 0.5)
p: 1.0 y = a * 1.0 x^(2.0) + b * 1.0 x + c