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Mathematics 7 Online
OpenStudy (anonymous):

How to figure the truth table for the given: (p^r) right arrow (qvr)

terenzreignz (terenzreignz):

We need to separate it into its components... Like, those involving single variables first, like, p, q, and r. Then, those involving single operators, like p^q, and qvr And finally, work your way until ultimately, we get the last (whole) statement.... I understand that that may not have made much sense, so let's just demonstrate...

OpenStudy (anonymous):

I was able to separate in to columns, just don't know if I have the "IF" column correct. May I share my answers with you from top to bottom and see if that is correct?

terenzreignz (terenzreignz):

By all means... ^_^

OpenStudy (anonymous):

T T F F F F T T

terenzreignz (terenzreignz):

Wait, this is the top row?

terenzreignz (terenzreignz):

Your truth-table looks something like this, right?

terenzreignz (terenzreignz):

\[\large \left[\begin{matrix}p&q&r&&p\land q&&q\lor r&&&(p\land q) \rightarrow(q\lor r)\\?&?&?&&?&&?&&&?\\?&?&?&&?&&?&&&?\\?&?&?&&?&&?&&&?\\?&?&?&&?&&?&&&?\\?&?&?&&?&&?&&&?\\?&?&?&&?&&?&&&?\\?&?&?&&?&&?&&&?\\?&?&?&&?&&?&&&?\end{matrix}\right]\]

OpenStudy (anonymous):

Something like that. The answers I sent are what would go in the right arrow column.

terenzreignz (terenzreignz):

I see... LOL Well, unfortunately, it won't make sense to me because I don't know what goes in the first three columns (because what goes in the first three columns depends entirely on you) So, is it like this? \[\large \left[\begin{matrix}p&q&r&&p\land q&&q\lor r&&&(p\land q) \rightarrow(q\lor r)\\\color{green}T&\color{green}T&\color{green}T&&?&&?&&&?\\\color{green}T&\color{green}T&\color{red}F&&?&&?&&&?\\\color{green}T&\color{red}F&\color{green}T&&?&&?&&&?\\\color{green}T&\color{red}F&\color{red}F&&?&&?&&&?\\\color{red}F&\color{Green}T&\color{green}T&&?&&?&&&?\\\color{red}F&\color{green}T&\color{red}F&&?&&?&&&?\\\color{red}F&\color{red}F&\color{green}T&&?&&?&&&?\\\color{red}F&\color{red}F&\color{red}F&&?&&?&&&?\end{matrix}\right]\] <pants> points for effort lol so... is that how your first three columns look like?

OpenStudy (anonymous):

Yes, they do, so I'm on the right track!!! Yay. Now for the rest of it...

terenzreignz (terenzreignz):

Might as well, yeah? What do you have for the fourth column? :)

OpenStudy (anonymous):

T F T F F T F T

terenzreignz (terenzreignz):

Fourth column? This one? \[\large \left[\begin{matrix}p&q&r&&\color{blue}{p\land q}&&q\lor r&&&(p\land q) \rightarrow(q\lor r)\\\color{green}T&\color{green}T&\color{green}T&&\color{blue}?&&?&&&?\\\color{green}T&\color{green}T&\color{red}F&&\color{blue}?&&?&&&?\\\color{green}T&\color{red}F&\color{green}T&&\color{blue}?&&?&&&?\\\color{green}T&\color{red}F&\color{red}F&&\color{blue}?&&?&&&?\\\color{red}F&\color{Green}T&\color{green}T&&\color{blue}?&&?&&&?\\\color{red}F&\color{green}T&\color{red}F&&\color{blue}?&&?&&&?\\\color{red}F&\color{red}F&\color{green}T&&\color{blue}?&&?&&&?\\\color{red}F&\color{red}F&\color{red}F&&\color{blue}?&&?&&&?\end{matrix}\right]\]

OpenStudy (anonymous):

I just realized that you have the problem wrong. Column 4 should be p^r

terenzreignz (terenzreignz):

Whoops.. apologies... good thing I haven't filled in that table yet ^_^ \[\large \left[\begin{matrix}p&q&r&&\color{blue}{p\land r}&&q\lor r&&&(p\land r) \rightarrow(q\lor r)\\\color{green}T&\color{green}T&\color{green}T&&\color{blue}?&&?&&&?\\\color{green}T&\color{green}T&\color{red}F&&\color{blue}?&&?&&&?\\\color{green}T&\color{red}F&\color{green}T&&\color{blue}?&&?&&&?\\\color{green}T&\color{red}F&\color{red}F&&\color{blue}?&&?&&&?\\\color{red}F&\color{Green}T&\color{green}T&&\color{blue}?&&?&&&?\\\color{red}F&\color{green}T&\color{red}F&&\color{blue}?&&?&&&?\\\color{red}F&\color{red}F&\color{green}T&&\color{blue}?&&?&&&?\\\color{red}F&\color{red}F&\color{red}F&&\color{blue}?&&?&&&?\end{matrix}\right]\]

terenzreignz (terenzreignz):

Sorry about that, just woke up XD

OpenStudy (anonymous):

That's okay. I've got a massive migraine and want to make sure I completely understand this. And being that I am a visual learner, it really helps for someone to walk through this step by step with me. So I'm in no rush. Go splash some water on your face if you need to!!

terenzreignz (terenzreignz):

But the column is still incorrect, however... keep in mind that we have a logical conjunction symbol \(\Large \land\) with the fourth column. Logical conjunction: fancy word for 'AND'. So, it'll only be true for the rows where both p AND r are true. And if I'm not mistaken, those are the first and third rows only...

terenzreignz (terenzreignz):

Did that make sense? lol

OpenStudy (anonymous):

Yes that did. Now with that in mind, let me figure the last column and I'll post in a quick sec.

terenzreignz (terenzreignz):

Wait, just to be clear, may I know your revised fourth column?

OpenStudy (anonymous):

Yes, it's: T F T F F F F F

terenzreignz (terenzreignz):

Oh okay :D What about the fifth column?

OpenStudy (anonymous):

Okay, I know I'll need help on this one. I know that the V is "or" but I'm just going to shoot you my initial answers and we'll go from there: T F F T T F F T

terenzreignz (terenzreignz):

Let me just fill in the fourth (for my own personal satisfaction :3 ) \[\large \left[\begin{matrix}p&q&r&&p\land r&&q\lor r&&&(p\land r) \rightarrow(q\lor r)\\\color{green}T&\color{green}T&\color{green}T&&\color{green}T&&?&&&?\\\color{green}T&\color{green}T&\color{red}F&&\color{red}F&&?&&&?\\\color{green}T&\color{red}F&\color{green}T&&\color{green}T&&?&&&?\\\color{green}T&\color{red}F&\color{red}F&&\color{red}F&&?&&&?\\\color{red}F&\color{Green}T&\color{green}T&&\color{red}F&&?&&&?\\\color{red}F&\color{green}T&\color{red}F&&\color{red}F&&?&&&?\\\color{red}F&\color{red}F&\color{green}T&&\color{red}F&&?&&&?\\\color{red}F&\color{red}F&\color{red}F&&\color{red}F&&?&&&?\end{matrix}\right]\]

OpenStudy (anonymous):

Whatever floats your boat!

terenzreignz (terenzreignz):

Now, as for the fifth, it's like the opposite of conjunction, it's disjunction...a fancy word for 'OR'. if 'AND' is only true if both components are true... 'OR' is only *false* if BOTH components are *false* Means it's true as long as at least one the components (q and r) is true. Care to revise the column? :)

OpenStudy (anonymous):

Yes, T T T F T T T F

terenzreignz (terenzreignz):

You catch on really quickly :D

terenzreignz (terenzreignz):

\[\large \left[\begin{matrix}p&q&r&&p\land r&&q\lor r&&&(p\land r) \rightarrow(q\lor r)\\\color{green}T&\color{green}T&\color{green}T&&\color{green}T&&\color{green}T&&&?\\\color{green}T&\color{green}T&\color{red}F&&\color{red}F&&\color{green}T&&&?\\\color{green}T&\color{red}F&\color{green}T&&\color{green}T&&\color{green}T&&&?\\\color{green}T&\color{red}F&\color{red}F&&\color{red}F&&\color{red}F&&&?\\\color{red}F&\color{Green}T&\color{green}T&&\color{red}F&&\color{green}T&&&?\\\color{red}F&\color{green}T&\color{red}F&&\color{red}F&&\color{green}T&&&?\\\color{red}F&\color{red}F&\color{green}T&&\color{red}F&&\color{green}T&&&?\\\color{red}F&\color{red}F&\color{red}F&&\color{red}F&&\color{red}F&&&?\end{matrix}\right]\]

OpenStudy (anonymous):

Thanks! It helps when I can write it down too. I'm taking notes as we go along.

terenzreignz (terenzreignz):

Finally, the implication... the one which isn't symmetrical... This one is only false when the LEFT component is true BUT the right component is false.. It's true otherwise... So, your revised sixth column is...? :D

OpenStudy (anonymous):

Working on it...

OpenStudy (anonymous):

Okay, so all of them are true!!!

OpenStudy (anonymous):

If that is correct, I'd like to know why it is I keep on second guessing myself. I had all TRUE's the very first time I did it!

terenzreignz (terenzreignz):

Yes, that is correct :) \[\large \left[\begin{matrix}p&q&r&&p\land r&&q\lor r&&&(p\land r) \rightarrow(q\lor r)\\\color{green}T&\color{green}T&\color{green}T&&\color{green}T&&\color{green}T&&&\color{blue}T\\\color{green}T&\color{green}T&\color{red}F&&\color{red}F&&\color{green}T&&&\color{blue}T\\\color{green}T&\color{red}F&\color{green}T&&\color{green}T&&\color{green}T&&&\color{blue}T\\\color{green}T&\color{red}F&\color{red}F&&\color{red}F&&\color{red}F&&&\color{blue}T\\\color{red}F&\color{Green}T&\color{green}T&&\color{red}F&&\color{green}T&&&\color{blue}T\\\color{red}F&\color{green}T&\color{red}F&&\color{red}F&&\color{green}T&&&\color{blue}T\\\color{red}F&\color{red}F&\color{green}T&&\color{red}F&&\color{green}T&&&\color{blue}T\\\color{red}F&\color{red}F&\color{red}F&&\color{red}F&&\color{red}F&&&\color{blue}T\end{matrix}\right]\] It can only mean that \[\Large (p\land r) \implies (q\lor r)\]is a logical truth/tautology Great job :D <fireworks> :3

terenzreignz (terenzreignz):

It just boils down to knowledge of the basic truth tables, like for 'and', 'or' 'implies' etc :D

OpenStudy (anonymous):

Thank you so much! I appreciate the tips and guidance! Talking me through it key. This is my very first truth table and wanted to make sure I was headed in the was at least headed in the right direction. I'm sure this won't be the first time I'll be tapping in to this site. This was awesome. Thanks again!!!

terenzreignz (terenzreignz):

No problem :) Welcome to Openstudy, and while you're at it, see if you can help out some people :D

OpenStudy (anonymous):

I'll do my best!

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