(adsbygoogle = window.adsbygoogle || []).push({}); [SOLVED] basic proof about inverse images of sets

1. The problem statement, all variables and given/known data

let f map X onto Y, and let A be a subset of X, B subset of Y

1) Prove that if y is in B, then f^(-1) (y) is in f^(-1) (B)

3. The attempt at a solution

1) I think I'm missing some two-line proof, because I'm getting nowhere and this is supposed to be simple. I just don't know where to start, so just a hint would be appreciated.

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

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!

# Homework Help: Basic proof about inverse images of sets

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