simplify
(2+3i)^3
F.4 maths: real numbers
2013-09-02 12:52 am
回答 (1)
2013-09-02 1:13 am
✔ 最佳答案
(2+3i)^3 =(2+3i)^2*(2+3i)
=[2^2+2(2)(3i)+(3i)^2]*(2+3i)
=(4+12i+9(-1))*(2+3i)
=(4+12i-9)*(2+3i)
=8+12i+24i+36i^2-18-27i
=8+12i+24i-36-18-27i
=-46+9i
2013-09-01 17:16:30 補充：
記著i^2=-1,
每逢見到i^2就將個數變負.
收錄日期: 2021-04-20 14:14:29
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20130901000051KK00159