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MathML 演示

Zoomable Math

HTML Content

```    <p>
<math display="block">
<mstyle id="zoomableMath" mathbackground="yellow">
<mrow>
<mi>x</mi>
<mo>=</mo>
<mfrac>
<mrow>
<mrow>
<mo>-</mo>
<mi>b</mi>
</mrow>
<mo>&#xB1;</mo>
<msqrt>
<mrow>
<msup>
<mi>b</mi>
<mn>2</mn>
</msup>
<mo>-</mo>
<mrow>
<mn>4</mn>
<mi>a</mi>
<mi>c</mi>
</mrow>
</mrow>
</msqrt>
</mrow>
<mrow>
<mn>2</mn>
<mi>a</mi>
</mrow>
</mfrac>
</mrow>
</mstyle>
[/itex]
</p>

```

JavaScript Content

```      function zoomToggle()
{
if (this.hasAttribute("mathsize")) {
this.removeAttribute("mathsize");
} else {
this.setAttribute("mathsize", "200%");
}
}

function load()
{
document.getElementById("zoomableMath").
addEventListener("click", zoomToggle, false);
}

window.addEventListener("load", load, false);```