yellowhighlighterr
Active Member
I got part a, but its application into part b confuses me. The answer is meant to be:
could i have some help pls? thanks
Factorials :/ (1 Viewer)
- Thread starter yellowhighlighterr
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I got part a, but its application into part b confuses me. The answer is meant to be:
could i have some help pls? thanks
telescoping sum.
yellowhighlighterr
Active Member
This is year 12? This is a year 11 question-
Vall
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can’t we just sub the identity from (i) into (ii)?
so the thing in part two becomes:
= (2! - 1!) + (3! - 2!) + (4!! - 3!) + … + ((n - 1)! - n!) + (n! - (n-1)!) + ((n+1)! - n!)
= (n+1)! - 1
(all the terms cancel out except those two)
so the thing in part two becomes:
= (2! - 1!) + (3! - 2!) + (4!! - 3!) + … + ((n - 1)! - n!) + (n! - (n-1)!) + ((n+1)! - n!)
= (n+1)! - 1
(all the terms cancel out except those two)