sqrt

实例

在本例中，我们将返回不同数的平方根：

<span class="token php language-php"><span class="token delimiter important"><?php</span>
<span class="token keyword">echo</span><span class="token punctuation">(</span><span class="token function">sqrt</span><span class="token punctuation">(</span><span class="token number">0</span><span class="token punctuation">)</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
<span class="token keyword">echo</span><span class="token punctuation">(</span><span class="token function">sqrt</span><span class="token punctuation">(</span><span class="token number">1</span><span class="token punctuation">)</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
<span class="token keyword">echo</span><span class="token punctuation">(</span><span class="token function">sqrt</span><span class="token punctuation">(</span><span class="token number">9</span><span class="token punctuation">)</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
<span class="token keyword">echo</span><span class="token punctuation">(</span><span class="token function">sqrt</span><span class="token punctuation">(</span><span class="token number">0.64</span><span class="token punctuation">)</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
<span class="token keyword">echo</span><span class="token punctuation">(</span><span class="token function">sqrt</span><span class="token punctuation">(</span><span class="token operator">-</span><span class="token number">9</span><span class="token punctuation">)</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
<span class="token delimiter important">?></span></span>

亲自试一试