Question

plz help

Answer 1

let\[f:X \rightarrow Y\] be an arbitrary function and let \[A \subseteq X , B \subseteq Y\]

Answer 2

this is a thorem .....

Answer 3

i guess

Answer 4

what should we do

Answer 5

wats the question

Answer 6

How is i that
\[f(A) \subseteq B\] if and only if \[A \subseteq f ^{-1}(B)\]

Answer 7

Is it not \[X = f ^{-1}(Y)\] ?

Answer 8

yeah you are right thats why i removed it,the thing is \[f^{-1}(Y)\] reverses the process
\[f(X)\] does