If A={1,2,3,4} and B={a,m,2,4,5} then R={(1,4),(2,5),(2,a),(4,m)} is a relation from A to B. Can someone please explain this? Why isn't (1,a),(1,m),etc included?
2007-04-02 16:45:34 · 4 answers · asked by CE08 1 in Science & Mathematics ➔ Mathematics
A relation on A x B is *any* set of ordered pairs (a,b) where a is in A and b is in B. It doesn't have to include *all* ordered pairs.
-pc
2007-04-02 16:49:38 · answer #1 · answered by Dr_Alpha 1 · 0⤊ 0⤋
Are you sure that the relation cited isn't (3,a) rather than (2,a)? It makes more sense. A relation of A and B is a coordinate (Ai, Bi), where Ai and Bi are acceptable values in the A and B sets. Generally, the "R" set should have 4 coordinate sets where for each specific value of Ai, there is one value of Bi. You could form other "R" sets, such as {(1,5), (2,4), (3,m), (1,a) }
2007-04-02 16:55:56 · answer #2 · answered by cattbarf 7 · 0⤊ 0⤋
A=domain and B=range. every domain should only have a unique range so as to consider the set of real numbers a relation and a function. when your domain is used twice in a set of numbers, then your set of real numbers is not a fumction.
2007-04-02 16:51:50 · answer #3 · answered by jhp_lei31 1 · 0⤊ 0⤋
the are the two first letters in the alphbet ahahhahahha i make myself laugh
2007-04-02 16:49:57 · answer #4 · answered by Anonymous · 0⤊ 0⤋