javascript atan() 计算数字的反正切值

<code class="language-javascript">Math.atan(number)</code>

<code class="language-javascript"><script type="text/javascript">
document.write(Math.atan(0.60) + "<br />")
document.write(Math.atan(-0.90) + "<br />")
document.write(Math.atan(20) + "<br />")
document.write(Math.atan(10) + "<br />")
document.write(Math.atan(-8) + "<br />")
document.write(Math.atan("bb"))
</script></code>

<code class="language-javascript">0.5404195002705842
-0.7328151017865066
1.5208379310729538
1.4711276743037347
-1.446441332248135
NaN</code>