messyscript/html小工具/求导.html

<!DOCTYPE html>
<html>
<head>
    <title>导数计算器</title>
    <script src="https://cdnjs.cloudflare.com/ajax/libs/mathjs/11.11.1/math.js"></script>
    <style>
        body { font-family: Arial, sans-serif; max-width: 800px; margin: 0 auto; padding: 20px; }
        .container { background-color: #f5f5f5; padding: 20px; border-radius: 8px; }
        input { width: 300px; padding: 8px; margin: 10px 0; }
        button { background-color: #4CAF50; color: white; padding: 10px 20px; border: none; border-radius: 4px; cursor: pointer; }
        button:hover { background-color: #45a049; }
        #result { margin-top: 20px; font-weight: bold; }
    </style>
</head>
<body>
    <div class="container">
        <h2>导数计算器</h2>
        <p>输入函数表达式（使用 x 作为变量）（ln x 请写成log(x)）:</p>
        <input type="text" id="functionInput" placeholder="例如：x^2 + 3*x + sin(x)" onkeypress="handleEnter(event)">
        <br>
        <button onclick="calculateDerivative()">计算导数</button>
        <div id="result"></div>
    </div>

    <script>
        function calculateDerivative() {
            const input = document.getElementById('functionInput').value;
            const resultDiv = document.getElementById('result');
            
            try {
                // 使用 math.js 计算导数
                const derivative = math.derivative(input, 'x');
                
                // 将结果转换为字符串并简化显示
                const resultString = derivative.toString()
                    .replace(/(\^)/g, '<sup>$1</sup>')
                    .replace(/\*/g, '');
                
                resultDiv.innerHTML = `导数结果：<span style="color: #2c3e50;">${resultString}</span>`;
            } catch (error) {
                resultDiv.innerHTML = `<span style="color: red;">错误：${error.message}</span>`;
            }
        }

        function handleEnter(event) {
            if (event.key === 'Enter') {
                calculateDerivative();
            }
        }
    </script>
</body>
</html>