Math Is Fun Forum

Amarylli$

Guest

functions and relations

hello all,

First question :

i have a R as such {A -> 1, A ->2, A -> 3, B -> 2, B -> 3, C -> 3}

my domain of R is {A, B, C} or {A, A, A, B, B, C} ?

i dont really understand this part

second question :

tis is off topic.. bt how to put partial function symbols, overriding symbols and such

Amarylli$

Guest

Re: functions and relations

woops foudn the solution for the second question ...so my real second question will be:

If f and g are elements of the set of
partial functions

and A is a subset of X , show that

i hope i got the symbols right

Last edited by MathsIsFun (2010-04-19 16:33:03)

Amarylli$

Guest

Re: functions and relations

mod! i need help im trying to place a maths question..im nt sure wht i did wrong..

MathsIsFun

Administrator

Registered: 2005-01-21

Posts: 7,713

Re: functions and relations

Was that what you wanted?

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"The physicists defer only to mathematicians, and the mathematicians defer only to God ..."  - Leon M. Lederman

Amarylli$

Guest

Re: functions and relations

oh yess..thanks!!

White_Owl

Member

Registered: 2010-03-03

Posts: 106

Re: functions and relations

i have a R as such {A -> 1, A ->2, A -> 3, B -> 2, B -> 3, C -> 3}

my domain of R is {A, B, C} or {A, A, A, B, B, C} ?

I am a little shaky on this topic myself, but...
Your R is from set {A, B, C} to set {1, 2, 3}. So the domain would be a union of those two sets: {A, B, C, 1, 2, 3}

pi_is_exactly3

Member

Registered: 2010-04-16

Posts: 3

Re: functions and relations

No your domain is the set from which the function transforms from ie   F: X->Y  the domain is X and the range is Y so in this case domain is the set {A,B,C}  and range is {1,2,3}

Amarylli$

Guest

Re: functions and relations

Oh ok..thnx..so it just takes the unique domain/range?

Amarylli$

Guest

Re: functions and relations

Second question solved i guess.. i'll post out the answer soon