serpentino di Newton cartesiana

y = 2 x /(x^2+1)

y = k d x /(x^2+1)

y = ( k d x ) /( x^2 + d^2)

k = 2
d = 3
f(x) = 2 * x / (x^(2) + 1)
g(x) = (k * d * x) / (x^(2) + 1)
h(x) = 2 * x / (x^(2) + 1)