並前往https://math.ymhs.tyc.edu.tw/chenjt99/ScrClass/1072/%E9%AB%98%E4%B8%89%E9%81%B8%E4%BF%AE%E4%B9%99%E4%B8%8A/%E7%BF%92%E4%BD%9C/Ch1.2%E6%9C%9F%E6%9C%9B%E5%80%BC%E3%80%81%E8%AE%8A%E8%97%9D%E8%A1%93%E8%88%87%E6%A8%99%E6%BA%96%E5%B7%AE.pdf
