Page No 11:
Question 8:
Let A and B be sets. Show that f: A × B → B × A such that (a, b) = (b, a) is bijective function.
f: A × B → B × A is defined as f(a, b) = (b, a).
.
∴ f is one-one.
Now, let (b, a) ∈ B × A be any element.
Then, there exists (a, b) ∈A × B such that f(a, b) = (b, a). [By definition of f]
∴ f is onto.
Hence, f is bijective.
