a = 0.5 (slider from -5 to 5)
x_{n1} = 3 (slider from -5 to 5)
x_{n2} = -4 (slider from -5 to 5)
f(x) = ((a * (x - x_{n1})) * (x - x_{n2}))
g(x) = (a * x^(2)) + ((a * ((-x_{n1}) - x_{n2})) * x) + ((a * x_{n1}) * x_{n2})