a = 0.8 (slider from -5 to 5, step 0.1)
b = 2 (slider from -5 to 5, step 0.1)
c = -1 (slider from -5 to 5, step 0.1)
f(x) = a * x^(2) + b * x + c
A = Intersect(f, xAxis, 2)
B = Intersect(f, xAxis, 1)
texto1: "f(x)=" + (LaTeX[f]) + ""
C = Extremum(f)
g = OrthogonalLine(C, e)
h = OrthogonalLine(C, d)
D = Intersect(e, g)
E = Intersect(d, h)
i = Segment(C, D)
j = Segment(C, E)
z1: x(B)
z2: x(A)
texto2: "Zeros: \{ " + (LaTeX[z1]) + " \, \, ;\, \,  " + (LaTeX[z2]) + " \}"
F = Intersect(f, d, 1)