lesson 7

Question 1

A – is an assignment of exactly one element of B to each element of A.

Answer 1

function f from A to B

Question 2

Functions are sometimes also called – or –.

Answer 2

mappings or transformations

Question 3

Functions are specified in many different ways. Sometimes we explicitly – (Fig. 1). Often, we give a formula, such as f x = x + 1, to define a function.

Answer 3

state the assignments

Question 4

If f is a function from A to B, we say that A is the – of f and B is the codomain of f.

Answer 4

domain

Question 5

If f a = b, we say that b is the – of a and
a is a – of b.

Answer 5

image, preimage

Question 6

if f is a function from A to B, we say that f –A to B.

Answer 6

maps

Question 7

A function f from A to B is called
– or –, if and only if for every
element b ∈ B there is an element a ∈ A with f a = b.

Answer 7

onto, or surjective

Question 8

The function f is a bijective or one-to-one correspondence, if it
is both – AND –.

Answer 8

injective AND surjective