15楼: Originally posted by dbb627 at 2013-11-06 16:13:20
如果只是20的话
mathematica可解
\int_0^{20} \text{Exp} \, dt-\int_0^{20} \text{Exp} \, dt

\frac{i \left(-1+e^{20 i w}\right)}{w}+\frac{(0.+1. i)+(0.909297+0.416147 i) e^{20. i w}}{0.1+w}

无穷积 ...

3楼: Originally posted by wind613 at 2013-11-04 11:21:34
不好意思。刚看到，第二个式子有点不清楚，麻烦你重发一个。