b = -1 (slider from -5 to 5, step 0.1)
a = 1.4000000000000004 (slider from -5 to 5, step 0.1)
f(x) = (0.5 * x^(2)) - 2
u_0 = -2.8 (slider from -10 to 20, step 0.1)
n = 6 (slider from 0 to 10, step 1)
Un = IterationList(f, u_0, n)
P = Sequence((Element[Un, i], 0), i, 1, n)
PourPlacerU_n = 0 rad (slider from 0 to 6.283185307179586, step 0.08726646259971647)
N = Sequence(Text["U_{" + (k - 1) + "}", Element[P, k] + (0.15; PourPlacerU_n)], k, 1, n)
L_h = Sequence(Vector[(Element[Un, i + 1], Element[Un, i + 2]), (Element[Un, i + 2], Element[Un, i + 2])], i, 0, n - 2, 1)
L_v = Union({Vector[(u_0, 0), (u_0, f(u_0))]}, Sequence[Segment[(Element[Un, k], Element[Un, k]), (Element[Un, k], Element[Un, k + 1])], k, 2, n, 1])