Functions Flashcards
1
Q
What is a codomain?
A
The possible outputs of a function
2
Q
What are images and pre images?
A
They are the direct pairs of inputs to outputs. For example, if a function maps a —> b then a is the pre image and b is the image
3
Q
What is the range of a function?
A
Let 𝐴 and 𝐵 be sets and 𝑓 be a function between them, 𝑓:𝐴→𝐵.
The range of 𝑓 is the set of all 𝑏∈𝐵 that have at least one pre-image in 𝐴
4
Q
Define a surjective function
A
𝑓:𝐴→𝐵 is surjective when all elements of B have at least one pre image in A
5
Q
Define an injective function
A
Every element in the range of the function is the image of a unique element from the domain.
6
Q
Define a bijective function
A
