math.github.io/12x.html at main · imimbert/math.github.io · GitHub

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<html>
    <head>
        <meta charset="utf-8">
        <title> 计算一元二次方程 </title>
    </head>
    <body>
        <p>计算形如 ax<sup>2</sup>+bx+c=0 的方程的根</p>
        <p id="result">此处显示结果</p>
        此处输入a:<input id="a"></br>
        此处输入b:<input id="b"></br>
        此处输入c:<input id="c">
        <button onclick="x12()">提交</button>
        <script>
            function x12(){
                var a,b,c,disc,x1,x2,p,q;
                a = document.getElementById("a").value;
                b = document.getElementById("b").value;
                c = document.getElementById("c").value;
                disc=Math.pow(b,2)-4*a*c;
                if(disc<0){
                    document.getElementById("result").innerHTML = "无实根"
                }else{
                    p=-b/(2*a);
                    q=Math.sqrt(disc)/(2*a);
                    x1=p+q;
                    x2=p-q;
                    res = "两个根分别为："+x1+","+x2;
                    document.getElementById("result").innerHTML = res;
                }
            }
        </script>
        <button onclick="javascript: window.location='index.html'">返回</button>
    </body>
</html>