Please explain step by step how and why
5e^(-i(t-15°)) + 5e^(i(t-15°))
becomes
10cos(t-15°)
收錄日期: 2021-04-23 23:06:56
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20201018174518AACS1mO