# Thread: Discrete Math Help, Reflexive or transitive?

1. ## Discrete Math Help, Reflexive or transitive?

This comes from the practice exam.

Let A = {0,1,2,3} and let R be a relation on A with R = {(1,1),(1,3),(2,2),(2,3),(3,2)}

a.) Draw the directed graph (digraph) which represents R

b.) is R reflexive? Why or why not?

c.) Is R transitive? Why or why not?

Any help is really appreciated.

2. ## Re: Discrete Math Help, Reflexive or transitive?

Originally Posted by ErikFBueno1990
This comes from the practice exam.
Let A = {0,1,2,3} and let R be a relation on A with R = {(1,1),(1,3),(2,2),(2,3),(3,2)}
a.) Draw the directed graph (digraph) which represents R
b.) is R reflexive? Why or why not?
c.) Is R transitive? Why or why not? ]
Don't you think that you should some effort?

I will tell you that for b & c, the answer is NO.

3. ## Re: Discrete Math Help, Reflexive or transitive?

Start by learning what reflexive and transitive mean. If you have a textbook with similar worked out examples, look at two or three. Not much help, I know, but it's the best and the most natural course of action. If you can't do this, say why and we'll help.

4. ## Re: Discrete Math Help, Reflexive or transitive?

A relation, R, on set X, is "reflexive" if and only if, for every x in X, (x, x) is in R. Is that true here? Why or why not?

A relation, R, on set X, is "transitive" if and only if, whenever (x, y) and (y, z) are in R so is (x, z). Is that true here? Why or why not?
(Note that (1, 3) and (3, 2) are both in R.)