Mathematics

Problem

Which one of the following conditions is both necessary and sufficient for a relation

f

from a non-empty set

A

to a set

B

to be a function? a) Every element of

A

is associated with at least one element of

B

. b) Every element of

B

is associated with exactly one element of

A

. c) Every element of

A

is associated with exactly one element of

B

. d) Every element of

A

is associated with at most one element of

B