无穷小方法对学生们的三大优点

    书是作者的思维结晶。无穷小微积分教材作者J.Keisler对其精心撰写的微积分教材的评价是比较客观的，而传统极限论微积分教材的作者却不敢出来“老王卖瓜，自卖自夸”。

J.Keisler在该书第一版序言中说：

The infinitesimal approach has three important advantages for the student.

First, it is closer to the intuition（直觉感知） which originally led to the calculus.

Second, the central concepts of derivative and integral become easier for the student to understand and use.

Third, it teaches both the infinitesimal and traditional approaches, giving the student an extra tool（额外的工具） which may become increasingly important in the future.

特别是上述第二点，无穷小方法更加易于被学生们理解与使用。菲氏微积分卫道士们敢于站出来这样说吗？

    还原微积分的历史原貌！

袁萌  7月14日