首页 >> 网页特效 >> 计数转换 >> 正文
来源: 不详 | 时间: 2006-1-15 19:13:05 | 人气:
二元一次方程的解答程序
要完成此效果需要两个步骤
第一步：把如下代码加入到<head>区域中
<SCRIPT LANGUAGE="JavaScript"><!-- Beginvar rootparti;var rootpart;var det;var rootparti1;var rootparti2;var a;var b;var c;var x1;var x2;var i = "i";function checkQuad() {var a = document.fquad.fa.value;var b = document.fquad.fb.value;var c = document.fquad.fc.value;if (a == 0 && c != 0) {x1 = -c / b;x2 = "Not a quadratic equation, but here is your answer for x";document.fquad.x1.value=x1;document.fquad.x2.value=x2;}else if (a == "" && c != 0) {x1 = -c / b;x2 = "Not a quadratic equation";document.fquad.x1.value=x1;document.fquad.x2.value=x2;}else {quad(); }}function quad() {var a = document.fquad.fa.value;var b = document.fquad.fb.value;var c = document.fquad.fc.value;det = Math.pow(b,2) - 4 * a * c;rootpart = Math.sqrt(det) / (2 * a);rootparti = (Math.sqrt(-det) / (2 * a)) + i;if (parseFloat(rootparti) < 0) {rootparti1 = rootparti;rootparti2 = (-1 * parseFloat(rootparti)) + i;}else {rootparti1 = (-1 * parseFloat(rootparti)) + i;rootparti2 = rootparti;}if (rootparti1 == "1i") {rootparti1 = i;rootparti2 = "-i";}else if (rootparti1 == "-1i") {rootparti1 = "-i";rootparti2 = i;}if (det == 0) {x1 = x2 = -b / (2 * a);}else if (det > 0) {x1 = (-b + Math.sqrt(det)) / (2 * a);x2 = (-b - Math.sqrt(det)) / (2 * a);}else if ((-b / (2 * a)) == 0) {x1 = rootparti1;x2 = rootparti2;}else {x1 = (-b / (2 * a) + " + " + rootparti1);x2 = (-b / (2 * a) + " + " + rootparti2);}document.fquad.x1.value=x1;document.fquad.x2.value=x2;}// End --></script>
第二步：把如下代码加入到<body>区域中
<form name=fquad> <table align="center"> <tr><td><h2><input name=fa size=4> <font color="#33FF33">x<SUP>2</SUP>+</font> <input name=fb size=4> <font color="#33FF33"> x +</font> <input name=fc size=4> <font color="#33FF33">= 0</font> <input type=button value="求值" onClick="checkQuad()"> <input type=reset value="重填"></h2></td></tr><tr><td> <h2> <font color="#33FF33">x<sub>1</sub>=</font><input name=x1 size=45><br> <font color="#33FF33">x<sub>2</sub>= </font><input name=x2 size=45></h2></td></tr></table></form>
