Understand Euler equations and Fourier series formula

Original link: http://www.cnblogs.com/zoneofmine/p/10852367.html

 

Make a note of, the following article explains very clear:

 

Euler's formula:

https://www.matongxue.com/madocs/8.html

 

Fourier transform

https://www.matongxue.com/madocs/619.html

OR

https://www.zhihu.com/question/19714540

 

Reproduced in: https: //www.cnblogs.com/zoneofmine/p/10852367.html