又有4道數學題唔識做呀><
pls~help me!
Q1.解下列方程
6x^2 (x-2) = 5x + x^2
(x-1)^2 = k^2 (x+k)
Q2.設n為正整數. 若(5 + x^2)^n 按x的升冪序展式中第3頂的係數為9375, 試找出n的值,
Q3.證明 (n-1)C(r-1) + (n-1)C(r) = nCr
註: (n-1)C(r-1) = (n-1)! / (n-1 - r-1)!(r-1)!
Q4.化簡 (n+1)C(3) - (n-1)C(3)
註: (n+1)C(3) = (n+1)! / (n+1 - 3)!(3)!
又有4道數學題唔識做...
2010-08-20 8:54 am
回答 (1)
2010-08-20 9:50 pm
✔ 最佳答案
As follows:圖片參考：http://i707.photobucket.com/albums/ww74/stevieg90/01-156.jpg
圖片參考：http://i707.photobucket.com/albums/ww74/stevieg90/02-130.jpg
圖片參考：http://i707.photobucket.com/albums/ww74/stevieg90/03-104.jpg
2010-08-20 13:50:38 補充：
http://i707.photobucket.com/albums/ww74/stevieg90/01-156.jpg
http://i707.photobucket.com/albums/ww74/stevieg90/02-130.jpg
http://i707.photobucket.com/albums/ww74/stevieg90/03-104.jpg
收錄日期: 2021-04-22 00:48:53
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20100820000051KK00091