Unformatted text preview: f is onto. Let T ∈ P ( B ) and let S = { x ∈ A  f ( x ) ∈ T } . Then g ( S ) = T , and g is onto. If f is not onto B , let y ∈ B − f ( A ). Then there is no subset S of A such that g ( S ) = { y } . 6. Suppose g : A → B and f : B → C , where f g is 11 and g is 11. Must f be 11? Ans: No. 7. Suppose g : A → B and f : B → C , where f g is 11 and f is 11. Must g be 11? Ans: Yes....
View
Full Document
 Summer '11
 NA
 Math

Click to edit the document details