並前往https://math.ymhs.tyc.edu.tw/chenyan/TeaPlan108/Contns/1081/%E9%AB%98%E4%B8%80%E4%B8%8A/Ch1/Ch1.3%E5%BC%8F%E5%AD%90%E7%9A%84%E9%81%8B%E7%AE%97(%E4%B8%8A%E8%AA%B2).pdf
