求证 (14 19:41:33)求证:Ank+kAnk-1=An+1k

来源:学生作业帮助网 编辑:六六作业网 时间:2024/08/28 18:08:19
求证(1419:41:33)求证:Ank+kAnk-1=An+1k求证(1419:41:33)求证:Ank+kAnk-1=An+1k求证(1419:41:33)求证:Ank+kAnk-1=An+1k展

求证 (14 19:41:33)求证:Ank+kAnk-1=An+1k
求证 (14 19:41:33)
求证:Ank+kAnk-1=An+1k

求证 (14 19:41:33)求证:Ank+kAnk-1=An+1k
展开:
Ank= (n-0)(n-1)(n-2)*…*(n-k+2)(n-k+1)
kAnk-1= k(n-0)(n-1)(n-2)*…*(n-k+2)
提取(n-0)(n-1)(n-2)*…*(n-k+2)
Ank+kAnk-1=(n-0)(n-1)(n-2)*…*(n-k+2)*(n-k+1+k)
=(n+1)(n-0)(n-1)(n-2)*…*(n-k+2)
=An+1k