Discrete Structures Week 7 Flashcards
1
Q
map/function
A
V- x C- A, E a unique y C- B such that f(x) = y
2
Q
domain and codomain
A
domain -> codomain
3
Q
cartesian product
A
sets A and B
A x B = { (a,b) | a C- A, b C- B}
4
Q
A^2
A
if A=B then A x B = A^2
5
Q
A^3
A
A^2 x A
= { (a,b,c) | a,b,c C- A}
6
Q
A^n
A
= {a1,a2,…,an | ai C- A for V- i}
7
Q
graph of function
A
= { (x,f(x)) | x C- A}
8
Q
A x B = B x A ?
A
no
example on notes
9
Q
not in the image means
A
no preimage
10
Q
no preimage means
A
not in image
11
Q
image
A
= { f(x) | x C- A } c_ B
12
Q
preimage/inverse image
A
f ^-1 (y) = { x | f(x) = y }
13
Q
identity map
A
f : Z -> Z
x |-> x
14
Q
know how to graph a function and come up with its set notation
A
:)
15
Q
continuous vs just dots
A
depends on the domain and codomain
