Boucle_non_bornee.ipynb

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   "source": [
    "*Lycée Saint-Adjutor - Auteur LANDAIS Avril 2021* ![Jupyter logo](https://upload.wikimedia.org/wikipedia/commons/3/38/Jupyter_logo.svg)"
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   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "# BOUCLE NON BORNEE \"WHILE\" EN LANGAGE PYTHON#"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "## Tant que"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "**Le principe de la boucle while, c’est d’exécuter un bloc d’instructions tant que (while in english) une condition donnée est vraie.\n",
    "Encore une fois commençons par un exemple** :"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 10,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
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     "text": [
      "15\n",
      "14\n",
      "13\n",
      "12\n",
      "11\n",
      "10\n",
      "9\n",
      "8\n",
      "7\n",
      "6\n",
      "5\n",
      "4\n"
     ]
    }
   ],
   "source": [
    "k=15\n",
    "while k>3:\n",
    "    print(k)\n",
    "    k=k-1"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "Change la valeur de k , relance le programme et observe ls différences.\n",
    "\n",
    "**Que se passe t-il si k<=3 ?**"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "Un nouvel exemple de boucle 'tant que' avec le module randint(a,b) qui permet de générer un entier aléatoire entre a et b"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 15,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "13\n",
      "4\n",
      "11\n",
      "6\n",
      "1\n",
      "11\n",
      "11\n",
      "12\n",
      "8\n",
      "9\n",
      "8\n",
      "9\n",
      "3\n",
      "13\n",
      "6\n",
      "3\n",
      "8\n",
      "13\n",
      "2\n"
     ]
    }
   ],
   "source": [
    "from random import randint\n",
    "k=13\n",
    "while k!=2:\n",
    "    print(k)\n",
    "    k=randint(0,13)\n",
    "print(k) # cette dernière ligne permet de faire afficher la dernière valur de k qui est égal à 2#"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "Que permet de faire ce code ?"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "**A vous  de créer un code dans la cellule ci-dessous avec pour consigne:**  \n",
    "k est un entier aléatoire entre 0 et 25 et on veut afficher k tant que k est supérieur ou égal à 10 "
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": []
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "On veut par exemple comparer la quantite A= ${k^3}-{12k^2}$  avec la quantité B= ${4 k^2}+{2k}$ \n",
    "k est un entier naturel\n",
    "\n",
    "Comme on ne sait pas quand A < B on va réaliser une boucle while\n"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 1,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "-40 20 2\n",
      "-81 42 3\n",
      "-128 72 4\n",
      "-175 110 5\n",
      "-216 156 6\n",
      "-245 210 7\n",
      "-256 272 8\n",
      "-243 342 9\n",
      "-200 420 10\n",
      "-121 506 11\n",
      "0 600 12\n",
      "169 702 13\n",
      "392 812 14\n",
      "675 930 15\n",
      "1024 1056 16\n",
      "1445 1190 17\n",
      "la quantite A dépasse B dès que k dépasse  17\n"
     ]
    }
   ],
   "source": [
    "k=1 \n",
    "A=-11\n",
    "B=6\n",
    "while A <B:\n",
    "    k=k+1\n",
    "    A=k**3-12*k**2\n",
    "    B=4*k**2+2*k\n",
    "    print (A , B , k)\n",
    "print(\"la quantite A dépasse B dès que k dépasse \", k)"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "Décris ce que fait ce programme."
   ]
  }
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