difference equation approximation的用法和样例：
- These results generalize and improve some known results about both neutral and delay difference equation.
- A kind of ordinary difference equation that can be transferred to Euler equation, often appears in polar coordinates solution of elastic problems.
- At the same time, by solving the difference equation at real time, the rules of the air contaminant distribution along the tunnel are revealed.
- Because of error by dispersing albinism differential equation, the response of difference equation is changed relative to differential equation.
- After that,the difference equation and b ou ndary condition were derivated and the solution was analyzed.Finally, one numer ic example was given.