- #1
Berrius
- 19
- 0
Homework Statement
f: X -> Y is a map from X to Y. And A, B subset X are random subsets of X. Proof the following:
a) if A subset B then f(A) subset f(B)
The Attempt at a Solution
(1)Take an arbitrary element x in f(A).
(2)For every x there has to be a y in A so that f(y)=x
(3)From A subset B: for every y in A, y in B
(4)So for every x in f(A) there has to be a y in f(B)
(5)So f(A) subset f(B)
I'm terrible at this, I came up with this proof but I'm wondering if my reasoning from step 3 to 4 is correct. Can someone help me?
Thanx in advance!