→ yhliu:f(1+h)=h*(f(1+h)/h) when h nonzero, so125.233.153.232 12/08 00:17
→ yhliu:lim f(1+h) = 0, so f(1)=0.125.233.153.232 12/08 00:17
→ yhliu:Then, f'(1)=5 by definition.125.233.153.232 12/08 00:18
→ YmemY:對吼..我又笨了XD 218.170.60.247 12/08 00:36
→ debdeb:謝謝 218.171.161.99 12/08 14:13