Difference between revisions of "1993 IMO Problems/Problem 5"

(Solution)
(Tag: Replaced)
 
(3 intermediate revisions by one other user not shown)
Line 1: Line 1:
 
==Problem==
 
==Problem==
 +
Let <math>\mathbb{N} = \{1,2,3, \ldots\}</math>. Determine if there exists a strictly increasing function <math>f: \mathbb{N} \mapsto \mathbb{N}</math> with the following properties:
 +
 +
(i) <math>f(1) = 2</math>;
 +
 +
(ii) <math>f(f(n)) = f(n) + n, (n \in \mathbb{N})</math>.
  
 
==Solution==
 
==Solution==
 +
Here is my Solution https://artofproblemsolving.com/community/q2h62193p16226748
 +
 +
Find as ≈ Ftheftics
 +
==Video solution==
 +
 +
https://youtu.be/IfCBp0608p8
 +
 +
==See Also==
 +
 +
{{IMO box|year=1993|num-b=4|num-a=6}}

Latest revision as of 11:30, 21 November 2023

Problem

Let $\mathbb{N} = \{1,2,3, \ldots\}$. Determine if there exists a strictly increasing function $f: \mathbb{N} \mapsto \mathbb{N}$ with the following properties:

(i) $f(1) = 2$;

(ii) $f(f(n)) = f(n) + n, (n \in \mathbb{N})$.

Solution

Here is my Solution https://artofproblemsolving.com/community/q2h62193p16226748

Find as ≈ Ftheftics

Video solution

https://youtu.be/IfCBp0608p8

See Also

1993 IMO (Problems) • Resources
Preceded by
Problem 4
1 2 3 4 5 6 Followed by
Problem 6
All IMO Problems and Solutions