- #1
simmonj7
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Homework Statement
When f: A -> B and S ⊆ B, we definte If(S) = { x ∈ A: f(s) ∈ S}. Let X and Y be subets of B.
a) Determine whether must equal If(X) ∪ If(Y).
b) Determine whether If(X ∩ Y) must equal If(X) ∩ If(Y).
Homework Equations
The definition of an inverse image is stated in the problem.
The Attempt at a Solution
So far I have tried to draw the schematic representation of the problem and didn't really get anything out of that.
Then I tried messing around with some proofs by saying "Choose an arbitrary x in If(X ∪ Y). Then, x = f(a) for some a in X ∪ Y." And then from there are I start questioning myself and don't know if I should continue/where I should go.
Thanks