Originally posted by pengyehui at 2011-06-28 21:37:31:
结论不正确
1. 假设题目中的e^rt表示e^{rt}, 则 ln(e^{rt}/(1+r)^t)=t(r-ln(1+r))趋于无穷，不趋于0
2.假设e^rt=t*e^r, e^rt/(1+r)^t趋向于0，只要r>-1

Originally posted by jfili at 2011-06-29 20:23:18:
明明是r趋近于0 后者可以是前者的近似
你怎么问成是t趋近与正无穷呢