def BiRegRoot(Fun, a, b, ErrMax):
    MAX_ITER = 1000
    last_ans = (a + b) / 2
    for i in range(MAX_ITER):
        c = (a * Fun(b) - b * Fun(a)) / (Fun(b) - Fun(a))
        a, b = b, c
        ans = (a + b) / 2
        err = abs((ans - last_ans) / last_ans)
        if err < ErrMax:
            return ans
        last_ans = (a + b) / 2
        print(i, " : ", ans)
    return ans