<?php
/**
 * Created by PhpStorm.
 * User: an2n
 * Date: 29/09/2016
 * Time: 20:14
 */


$fire = 4;
$pi = 4 - (4/3);

for($i = 5; round($pi,6) != 3.141592; $i+=2){
    $pi += ($fire/($i));
    $pi -= ($fire/($i+=2));
}

echo "Min PI funksjon gir: " . round($pi, 6) ."</br>";

echo "PHP sin innebygged PI funksjon gir: ". round(pi(),6);


?>
<form action="" method="get">
    <input type="number" name="tall">
    <input type="submit" value="Generer primtall" name="trykk">
</form>
<form action="" method="get">
    <input type="number" name="tall2">
    <input type="submit" value="Sjekk om primtall" name="trykk2">
</form>

<?php

if(isset($_GET["trykk"])){
    for($i = 1; $i < $_GET["tall"]; $i++){
        if($i % 3 == 0){
            echo $i . "</br>";
        }
    }
}

if(isset($_GET["trykk2"])){
   if($_GET["tall2"] % 3 == 0){
       echo "Er et primtall";
   }
    else{
        echo "Er ikke et primtall";
    }
}