HMMT 二月 2001 · 冲刺赛 · 第 21 题
HMMT February 2001 — Guts Round — Problem 21
题目详情
- [10] Evaluate .
( − 2)ii =1
英文原题
[10] Evaluate ∞ ∑
i =1
( i +1)( i +2)( i +3)
( − 2) i .
解析
英文解析
- [10] Evaluate .
( − 2)ii =1
Solution: This is the power series of expanded about x = 0 and evaluated at 6
(1+ x )4
x = − , so the solution is 96 .1 2