並前往https://math.ymhs.tyc.edu.tw/chenjt99/ScrClass/1041/%E7%BF%92%E4%BD%9C/%E9%AB%98%E4%B8%80%E4%B8%8A/%E7%BF%92%E4%BD%9C%E7%94%B2/3-1%20%E6%8C%87%E6%95%B8.pdf