# Assignment Assistance

• Mar 6th 2013, 03:09 PM
rtrumpow
Assignment Assistance
Hello;

I have just started Discrete Math this week. I am watching Discrete Mathematics video via YouTube and still a little hazy on some of my assignment questions. I am reading the text in the chapter prior to starting my assignments and while gaining a little bit of knowledge; am still lost on some of these questions.

"Rewrite each of the following statments so that it is clear that each is an implication." ***I am not sure if my thinking is accurate on this question.***
(b) The product of rational numbers is rational. (My answer: "The product of irrational numbers is not rational.")

"Write down the converse and the contrapositive of each of the following implications."
(d) If n is an odd integer, then n2 + n - 2 is an even integer. (I did not write down an answer on this one. I have no idea what is being requested.)

Thank you for any assistance. I apologize if this is basic questions; I am a little lost in this class.

Regards,
-RT
• Mar 6th 2013, 03:27 PM
Plato
Re: Assignment Assistance
Quote:

Originally Posted by rtrumpow
"Rewrite each of the following statments so that it is clear that each is an implication." ***I am not sure if my thinking is accurate on this question.***
(b) The product of rational numbers is rational. (My answer: "The product of irrational numbers is not rational.")

FORGET Discrete Mathematics video via YouTube. That is a total waste of your time.

And no, your thinking is not accurate on this question.
To make an implication formal it should be in the if-then form.

If each of $\displaystyle a~\&~b$ is a rational number then $\displaystyle a\cdot b$ is rational.

Now it does not need to be exactly that. But that is the general idea.
• Mar 8th 2013, 04:06 AM
rtrumpow
Re: Assignment Assistance
Thanks for the assistance and correction to my first question.
• Mar 8th 2013, 12:16 PM
emakarov
Re: Assignment Assistance
Quote:

Originally Posted by rtrumpow
"Write down the converse and the contrapositive of each of the following implications."
(d) If n is an odd integer, then n2 + n - 2 is an even integer. (I did not write down an answer on this one. I have no idea what is being requested.)

See Wikipedia about converse and contrapositive. However, it is better to read your textbook or lecture notes.