#!/usr/bin/env python3
# -*- coding: utf-8 -*-
"""
Created on Fri Jan 10 09:17:36 2020

@author: suwako
"""

import scipy
import numpy as np
def dichotomie(f, a, b, epsilon=1e-15):
    g, d = a, b
    while abs(g - d) > 2*epsilon:
        m = (g+d)/2.
        if f(g)*f(m) <= 0:
            d = m
        else:
            g = m
    return (g+d)/m