並前往https://pclevinblog.pixnet.net/blog/post/314562100-javascript-%E6%95%B8%E5%AD%B8%E9%A1%9E-%E6%B1%82%E5%B9%B3%E6%96%B9%E6%A0%B9%E5%87%BD%E6%95%B8-%E4%BD%BF%E7%94%A8math.sqrt%28%29