十一月 08 2005
解二元一次方程式
此php程式可以自動算出2元一次方程式
ax2 + bx + c = 0
x的值
< ?php
if ($_POST["submit"] == "提交"){
$a = (int)$_POST["a"];
$b = (int)$_POST["b"];
$c = (int)$_POST["c"];
if ($a == "" || $b == "" || $c == ""){
echo "各欄位請勿空值";
exit;
}
$d = ($b*$b)-(4*$a*$c);
if ( $d < 0 ){
$X = "虛根";
}else{
$X.=(-$b+sqrt($d))/(2*$a);
$X.=" OR ";
$X.=(-$b-sqrt($d))/(2*$a);
}
}
?>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
<title>計算式</title>
</meta></head>
<body>
<form method="POST" action="">
<p>ax<sup>2</sup> + bx + c = 0</p>
<p><input type="text" name="a" size="5" value="<?= $a;?/>">X<sup>2</sup> + <input type="text" name="b" size="5" value="<?= $b;?/>">X + <input type="text" name="c" size="5" value="<?= $c;?/>"> = 0</p>
<p>X = <font color="#FF0000">< ?= $X;?></font></p>
<p><input type="submit" value="提交" name="submit"/></p>
</form>
</body>
</html>有一篇回應
請問這要怎麼用??
可以的話請回所留mail