數學(Functions)@2
回答 (1)
2009-02-06 3:58 am
✔ 最佳答案
f(x) = x^2-2xf(k-2) = (k-2)^2-2(k-2)
= k^2-4k+4-2k+4
= k^2-6k+8
f(k+2) = (k+2)^2-2(k+2)
= k^2+4k+4-2k-4
= k^2+2k
f(k-2)-f(k+2) = (k^2-6k+8)-(k^2+2k)
= k^2-6k+8-k^2-2k
= -8k+8
[OR = -8(k-1)]
收錄日期: 2021-04-13 16:26:02
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20090205000051KK01720