Donner un encadrement d'amplitude 10 de <i>f</i>($x1;$y1).<br>

!form reply

  <center>
<input size=5 name=m value="$m"> 
&le;
<i>f</i>($x1;$y1)
&le;
<input size=5 name=M value="$M"> 
<br>
<br>
<input type=submit value="Envoyer"> 
</center>
</form>
