( u^2+u+1)(u^2-u+1)
要用因式分解做,謝謝!
唔識做功課3
2012-09-20 8:49 pm
回答 (1)
2012-09-20 10:06 pm
✔ 最佳答案
(u^2 + u + 1)(u^2 - u + 1)= [u^2 + u + 1][u^2 - u + 1]
= [u^2 + 1 + u][u^2 + 1 - u]
= [(u^2 + 1) + (u)][(u^2 + 1) - (u)]
= (u^2 + 1)^2 - (u)^2<= 因為 (a + b)(a - b) = a^2 - b^2
= (u^2)^2 + 2(u^2)(1) + (1)^2 - u^2
= u^4 + 2u^2 + 1 - u^2
= u^4 + u^2 + 1
參考: knowledge
收錄日期: 2021-04-13 18:58:49
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20120920000051KK00134