erreur max (non dynamique) en pourcents

Go!

dt = 0.002 (slider from 0 to 0.005, step 5.0E-4)
f(x) = If[0 ≤ x ≤ 6, ((2.5 * ℯ^((-x))) * x)]
er = 0.018526603387508618 (slider from -5 to 5, step 0.001)
ChampTexte1 = Textfield(er)