並前往https://www.sudoedu.com/zh/%E5%BE%AE%E7%A7%AF%E5%88%86%EF%BC%88calculus%EF%BC%89-%E8%A7%86%E9%A2%91%E8%AF%BE%E7%A8%8B/%E6%9E%81%E9%99%90%E4%B8%8E%E8%BF%9E%E7%BB%AD%EF%BC%88limits-and-continuity%EF%BC%89/%E5%87%BD%E6%95%B0%E5%9C%A8%E6%97%A0%E7%A9%B7%E8%BF%9C%E5%A4%84%E7%9A%84%E6%9E%81%E9%99%90-limits-at-infinity/