Relations and Functions
Matching exercise
Match the items on the right to the items on the left.
one-one functions
onto functions
one-one and onto functions
composition of functions
invertible functions
f(x1) = f(x2) ⇒ x1 = x2 ∀ x1, x2 ∈ X
if given any y ∈ Y, ∃ x ∈ X such that f(x) = y.
f is both one-one and onto.
f : A → B and g : B → C is the function gof : A → C given by gof(x) = g(f(x)) ∀ x ∈ A.
f is one-one and onto.