a = 0.1 (slider from 0.1 to 10, step 0.1)
c = 0.1 (slider from 0.1 to 20, step 0.1)
t = -6 (slider from -6 to 6, step 0.05)
d: y = a * x^(2) + t * x + c
P: ((-t) / (2 * a), (4 * a * c - t^(2)) / (4 * a))