sqrt
平方根
在本例中,我們將返回不同數的平方根:
<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>