It is difficult for learner to understand the concept of Riemannintegral which is defined by using the limit of Riemann sum.
用积分和的极限定义的黎曼积分对于初学者来说是一个很难理解的概念。
2
In this paper we give some simpler definitions of definite integral, and show that they are all equivalent to the definition of Riemannintegral.
本文给出了定积分的几个较简单的定义，并证明这些定义均与黎曼积分定义等价。
3
Based on Darboux theory, this paper discussed the integrability of the RiemannIntegral and provides a necessary and sufficient condition for integrability.