1.

Let A and B be sets. Show that `f" ":" "AxxB`,`BxxA`such that `f" "(a ," "b)" "=" "(b ," "a)`is bijective function.

Answer» In `f: AxxB to BxxA`
`f(a, b) = (b, a) AA (a, b) in A xx B`
Let `" " (a, b), (c, d) in AxxB`
and `" " f(a, b) = f(c,d)`
`rArr (b, a) = (d, c)`
`rArr b =d and a = c `
`rArr (a, b) = (c, d)`
`therefore f ` is one-one.
Again, for each `(a, b) in B xx A, (b, a) in A xx B` is such that
`therefore " " f(b, a) = (a, b)`
`therefore f` is onto.
Therefore, `f` is one-one onto function.


Discussion

No Comment Found