Question

5. Let X = {a, b, c) and Y = {d, e, f, g}.

Does the following arrow diagram determine a function from X to Y? Explain. (6 Pts)


b. What are the domain, and co-domain

Answer 1

@Shalante

@ganeshie8
@Hero

Answer 2

@IrishBoy123

Answer 3

Look at what a function does,

Answer 4

@pooja195

Answer 5

@aaronq

Answer 6

I am confused because it meets the two requirements

Answer 7

1. All x values have a y value

Answer 8

2. No same x value has two ys

Answer 9

but do they need to have the same number of elements in X and Y?

Answer 10

@SithsAndGiggles

Answer 11

?

Answer 12

two x values can have the same why but not vice versa i think

Answer 13

yes
another way to say it is a function can be many-to-one but not one-to-many

Answer 14

yes @welshfella but is that one a function?

Answer 15

Do the elements on X and Y need to be the same number?

Answer 16

what is different with this relation is that you have values of y not linked with a value of x.
To be honest i don't know for sure.

Answer 17

the co-domain, is all of the output values, the set contains all of the 'graphed' points that are mapped by the rule X-->Y, Plus possibly more.

Answer 18

Like say for example, if you have the function

f(x) = x^2

The Domain is all real numbers, the range of that is just numbers greater than zero...

Answer 19

http://www.mathsisfun.com/sets/domain-range-codomain.html

Answer 20

the co-domain though is all real numbers,

Answer 21

x ---->x^2, both can be any real number, but the actual image of the graph does not have negative values, so the co domain includes the negative values, the range is just positive values

Answer 22

so the whole set Y is the codomain

Answer 23

it does not matter that some elements are not used?

Answer 24

@welshfella

Answer 25

right, the co-domain possibly includes values that aren't graphed by the function

Answer 26

I found this kind of helpful :)
http://www.mathsisfun.com/sets/domain-range-codomain.html
If you scroll half-way down, the three green check marks.

Answer 27

f(x) = x^2

Domain - All Reals
Range - y >=0
co-domain - all reals

Answer 28

X ----> X^2

you can choose any number for X, domain
You can choose any number for X^2, co-domain
the results area always positive, Range or the actual graph

Answer 29

Yeah thanks ! I get it now