我想問x^3-y^3的公式是......
回答 (3)
2007-03-04 6:10 pm
✔ 最佳答案
x³士y³=(x士y)(x²干xy+y²)proof:
R.H.S.
=(x士y)(x²干xy+y²)
=x³干x²y+xy²士x²y-xy²士y³
=x³干x²y士x²y+xy²-xy²士y³
=x³士y³
The proof is completed.
2007-03-04 10:48 pm
(x-y)(x+y)(x-y)
2007-03-04 6:56 pm
x^3-y^3= (x-y)(x^2+xy+y^2)
x^3+y^3=(x+y)(x^2-xy+y^2)
x^3+y^3=(x+y)(x^2-xy+y^2)
收錄日期: 2021-04-13 16:11:09
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20070304000051KK00956