(adsbygoogle = window.adsbygoogle || []).push({}); 1. The problem statement, all variables and given/known data

Give an example of a map from the set N of positive integers to itself which

is surjective but not injective.

2. Relevant equations

3. The attempt at a solution

It's easy to come up with an example, but I'm not sure on notation.

Here's how I've written it, but I know it's not quite right. I'm sure you can see the function that I am meaning to give. Any help with the notation would be appreciated. If it's not clear what function I mean, let me know and I will put it into words :)

[tex]\lbrace f:f(1)=1, f(s)=s-1,s>1\rbrace[/tex]

**Physics Forums | Science Articles, Homework Help, Discussion**

Dismiss Notice

Join Physics Forums Today!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

# Function notation

**Physics Forums | Science Articles, Homework Help, Discussion**