# Define set from given function and a subset. Abstract math

1. Apr 3, 2012

### beatka6

1. The problem statement, all variables and given/known data
Let f: Z to ZxZ be the function defined f(t)=(3t, 3t+1) . Let B denote the subset of ZxZ defined by B={ (5m, 5m+1) : m is an element of Z}. Determine f^-1(B). This means that you should define set S with a property of S=f^-1(B). In addition, your definition of S should make no mention of the function f.

2. Relevant equations

3. The attempt at a solution
From what I understand first we have to find f(B), but B is a subset of ZxZ not Z therefore I don't know what to do with this. Please help.

2. Apr 5, 2012

### sunjin09

f^{-1}(B) is defined as {t$\in$Z | f(t)$\in$B}, i.e., the collection of t's such that f(t) is in B.

3. Apr 5, 2012

### jaostar13

It says that it should have no mention of f in the defined set.