előjel = 1 (slider from -1 to 1, step 2)
a = 1 (slider from -5 to 5, step 0.1)
b = -4 (slider from -8 to 8, step 1)
c = 3 (slider from -8 to 8)
f: y = ((előjel * a) * (x + b)^(2)) + c