Fix: Correct dichotimie

ex5.py

@@ -4,22 +4,22 @@ import numpy as np
 new_raph_steps = []
 dich_steps = []
 
+
 def f(x) -> float:
     return np.exp(x) - 2 * np.cos(x)
 
 
 def dichotomie(a, b, epsilon=1e-6, n=0) -> float:
     x = (a + b) / 2
-
-    delta = f(a) * f(x)
+    alpha = f(a) * f(x)
     dich_steps.append(x) # si on veut afficher les étapes
 
     if np.abs(b - a) <= epsilon:
         return x
 
-    if delta < 0:
+    if alpha < 0:
         return dichotomie(a, x, epsilon, n+1)
-    elif delta == 0:
+    elif alpha == 0:
         return x
     else:
         return dichotomie(x, b, epsilon, n+1)
@@ -46,13 +46,13 @@ def newton_raphson(x_0, epsilon, max_iter=1_000) -> float | None:
         if np.abs(fx) < epsilon:
             return x
         elif fpx == 0:
-            return None
+            raise RuntimeError("Dérivée nulle : échec de Newton-Raphson.")
         x = x - (fx / fpx)
         new_raph_steps.append(x)
         if np.abs(x - x_prev) < epsilon:
             return x
 
-    return None
+    raise RuntimeError(f"Newton-Raphson n'a pas convergé en {max_iter} itérations.")
 
 
 def ex1() -> None: