Relationships A Function?

Nov 2019
23
2
NYC
Are the following relationships a function?

R = {-2, 5}, {3, 5}, {6, 4}

S = {4, 5}, {6, 7}, {4, 5}

T = {9, 0}, {8, 7}, {9, -4}

R is a function.

S is a function.

T is not a function because 9 goes to two distinctive values, which are 0 and 4.

Is my reasoning correct?
 

Plato

MHF Helper
Aug 2006
22,475
8,643
Frankly, I would say that none of the three is a function.
The set theoretic definition of a function requires an initial set and a final set.
 
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Prove It

MHF Helper
Aug 2008
12,896
5,001
Frankly, I would say that none of the three is a function.
The set theoretic definition of a function requires an initial set and a final set.
It doesn't look well written, but I assume that each co-ordinate represents an input (x) value and an output (y) value.