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2題complex no. 急急
2010-09-12 11:10 pm
回答 (1)
2010-09-13 12:03 am
✔ 最佳答案
1. [(4 + 5i) - (-1 + 8i)](20 - i) / (1 - i)= (5 - 3i)(20 - i) / (1 - i)
= [5(20) + 5(-i) + (-3i)(20) + (-3i)(-i)] / (1 - i)
= (100 - 5i - 60i - 3) / (1 - i)
= (97 - 65i) / (1 - i)
= (97 - 65i)(1 + i) / (1 - i)(1 + i)
= [97 + 97i - 65i + 65] / [1^2 - i^2]
= (162 + 32i) / 2
= 81 + 16i
2. ( 8 + i sqrt5)^2
= 8^2 + 2(8)(i sqrt5) + (i sqrt5)^2
= 64 + 16i sqrt5 - 5
= 59 + 16i sqrt5
參考: Prof. Physics
收錄日期: 2021-04-19 23:14:00
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20100912000051KK00882