Logic

JeffM

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I don't understand what you mean.

Please post the complete exercise statement.

:confused:
There is no exercise statement. He is trying to find ways to contradict basic axioms.
 

pka

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There is no exercise statement. He is trying to find ways to contradict basic axioms.
I am very reluctant to call names. But Ryan$ takes the cake S/he is by any means of the imagination an InterNet TROLL.
Please, please follow that LINK. If anyone can argue that Ryan$ fails to fulfill that definition of a TROLL please post your justifications.
In the absent of any cogent defense I ask that Ryan$ be banded.
 

Otis

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… If anyone can argue that Ryan$ fails to fulfill that definition of a TROLL please post your justifications …
Ryan$ has the mind of a child.

… from equation logic … x=2y …
… logic [lets me] do whatever …
… I can think in general … so it's possible [that x≠2y]
:rolleyes:
 

JeffM

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mmm4444bot

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I suspect that he is a child. I have not seen malicious intent.
Agree!

We've asked Ryan$ to follow the guidelines, so tutors can know what he's talking about. I intend to start enforcing those requests.

😐
 

Subhotosh Khan

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Agree!

We've asked Ryan$ to follow the guidelines, so tutors can know what he's talking about. I intend to start enforcing those requests.

😐Not a basic face - neither an acidic face - just a neutral face (pH = 7) - as clear as water
 

Ryan$

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Hello every one, ! thanks alot for your answers !!!

for whom you think I troll, I said I'm not trolling in advance, I said I'm not that much smarter and everytime I post here I apologize before about thats questions !
I admit that I have a suck mind, but whatever, I want to learn, not to still dull.
 

Ryan$

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Hi guys, before you think that I troll, it's really serious and not trolling at all.
lets assume I have three equations like this:
(1) x=5
(2)x=3*m +6
(3) x+y=7
I conclude from first equation that x=5, ye? i'm find with this!
now I go to third equation, x+y=7 ! who said that I can refer to the first equation x=5 and assign it on that equation?
we already discuss "if we don't know anything about something, then we assume generally it's true" , so if it's true to not refer first equation x=5, and assign it on third equation x+y=7 , then why we are using/referring what we have from equation (1) to equation 3 while it's true to not refer?! (why it's true to not refer? because none tells me that I can refer equation (1) to equation (3), so generally what every possibility I take would be true .. so if I don't want to refer to first equation to solve equation (3), then it's true ... so why we aren't taking that possibility(to not refer to first equation in order to solve equation (3) )?!
 
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lev888

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The problem statement should instruct you to solve either
1. A set of equations or
2. A system of equations (simultaneous equations)
Only in the case of a system of equations can you use one equation to solve another - they have a common solution by definition.
 

JeffM

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Hi guys, before you think that I troll, it's really serious and not trolling at all.
lets assume I have three equations like this:
(1) x=5
(2)x=3*m +6
(3) x+y=7
I conclude from first equation that x=5, ye? i'm find with this!
now I go to third equation, x+y=7 ! who said that I can refer to the first equation x=5 and assign it on that equation?
It's a problem that YOU made up so you tell us whether or not you can refer to a previous equation.

we already discuss "if we don't know anything about something, then we assume generally it's true"
What in the world are you talking about? Who said that? It is WRONG.

, so if it's true to not refer first equation x=5, and assign it on third equation x+y=7 , then why we are using/referring what we have from equation (1) to equation 3 while it's true to not refer?! (why it's true to not refer? because none tells me that I can refer equation (1) to equation (3), so generally what every possibility I take would be true .. so if I don't want to refer to first equation to solve equation (3), then it's true ... so why we aren't taking that possibility(to not refer to first equation in order to solve equation (3) )?!
This is why people think you are trolling: none of that makes any sense at all.

I have a guess. You do not fully understand that in different problems x may, and usually does, refer to different numbers.
Variables are NOT numerals. 3 always refers to the same specific number. On the other hand, x refers to the same specific number only for the duration of a single problem.

I strongly suggest that you give us problems that come from your teacher or text and confuse you and then try to tell us what confuses you about those problems. The problems that you make up on your own make no sense and so do not allow us to see where exactly your confusion lies.
 

HallsofIvy

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Hi guys, before you think that I troll, it's really serious and not trolling at all.
lets assume I have three equations like this:
(1) x=5
(2)x=3*m +6
(3) x+y=7
I conclude from first equation that x=5, ye? i'm find with this!
now I go to third equation, x+y=7 ! who said that I can refer to the first equation x=5 and assign it on that equation?
Un- no one did! Where did you get that idea? Unless, of course, we are told that these are "simultaneous equations"- that is that the equations are true for the same values of x, y, and m.

we already discuss "if we don't know anything about something, then we assume generally it's true"
WHO discussed that? Because that's a really foolish thing to assume! "If we don't know anything about something" then we can't assume anything about it. UNLESS, again, we were told that these are simultaneous equations and are told that they are true for the same values of x, y, and m
.
, so if it's true to not refer first equation x=5, and assign it on third equation x+y=7 , then why we are using/referring what we have from equation (1) to equation 3 while it's true to not refer?! (why it's true to not refer? because none tells me that I can refer equation (1) to equation (3), so generally what every possibility I take would be true .. so if I don't want to refer to first equation to solve equation (3), then it's true ... so why we aren't taking that possibility(to not refer to first equation in order to solve equation (3) )?!
I don't understand what you are asking because you haven't said what problem you are trying to solve! You give three equations in x, y, and m. Are they "simultaneous equations"? If they are then they must all three be true for the
same values of x, y, and m. Since x= 5, x+ y= 5+ y= 7 so y= 2. Then x= 5= 3m+ 6 so 3m= 5- 6= -1 and m= -1/3. If we are told that these are "simultaneous equations" then x must be 5, y must be 2, and m must be -1/3. But we have to be told what problem we are solving!
 

Ryan$

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It's a problem that YOU made up so you tell us whether or not you can refer to a previous equation.



What in the world are you talking about? Who said that? It is WRONG.
but if it doesn't make sense why it's struggling me to not solve the problem properly ?!

well, if it's wrong as you said, then if I said "now, anyone who's bigger than 18age can enter this gate"
so if a person with red hat and his age is more than 18, he can enter the gate, why?! because he's bigger than 18age, and I didn't say anything else in my assumption, so if I didn't say anything else then anyone who's more than 18 age with other possibilities (like red hat for example) can enter the gate! .. I mean by "if we don't know=we assume in general" .. this case exactly we don't know more than condition "more than 18age" ..so other possibilities aside more than 18years old are possibilities and he can enter the gate.
so if we don't know anything about other conditions, we assume in general. on that case I used in my question on the thread above
 

Ryan$

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what do you mean by senseable?! not make sense? you mean "not logically" ?!
 

JeffM

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I do not want to get into the relationship between logic and mathematics. It is complicated. All I shall say is that logical implication is not what an equal sign means.

"If Toto is a dog, then Toto is an animal" is not contradicted by "If Toto is a dog wearing a collar, then Toto is an animal." These are statements about logical implication.

That does not mean that 3 = 3 + 1. That is just idiotic.

I suggest that you put your mind to learning what the meaning of the symbols in algebra means in algebra rather than trying to build some isomorphism between logic and elementary algebra.
 

Ryan$

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Messages
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but you didn't understand me !

if I concluded from equation (1) *doesn't matter what is the equation* , I concluded from it x=2y.
and I have second equation (2) 3y^2=5+x;
can I say that I have now the new equation aka "conclusion that I concluded from equation (1)" ? I mean can I use x=2y as a given information? if so, then why? we concluded it from equation (1), that doesn't mean that we can use it as a given information ! any help? here's my struggling !!

who said that I can go to the logic from first equation? who give me a permission for? logic of equation one is related to equation one and not related to other logic ..


NOTE-GIVEN ON THE QUESTION THAT EQUATIONS ARE SEQUENTIAL..

thanks alot
 

JeffM

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STOP MAKING UP YOUR OWN PROBLEMS. They make no sense. "doesn't matter what is the equation" Of course it matters what the equation is. Why do you conclude from some unspecified equation that x = 2y?

Give us problems from your text or teacher that confuse you.
 

HallsofIvy

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Jan 27, 2012
Messages
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if I concluded from equation (1) *doesn't matter what is the equation* , I concluded from it x=2y.
and I have second equation (2) 3y^2=5+x;
can I say that I have now the new equation aka "conclusion that I concluded from equation (1)" ? I mean can I use x=2y as a given information? if so, then why? we concluded it from equation (1), that doesn't mean that we can use it as a given information ! any help? here's my struggling !!

who said that I can go to the logic from first equation? who give me a permission for? logic of equation one is related to equation one and not related to other logic ..
IF you are told that these equations are all true for the same x and y THEN you can use the result of one in the other. But just writing several equation without saying that doesn't mean anything. Always post the entire problem, not just part, like posting equations without saying what is to be done with them!
 

Otis

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… logic of equation one is related to equation one and not related to other logic …
That's so wrong.

Why do you argue about given information? You were told that some quantity (represented by symbol x) is always twice as big as some other quantity (represented by symbol y). Why can't you accept that information as given?

:confused:
 

Ryan$

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That's so wrong.

Why do you argue about given information? You were told that some quantity (represented by symbol x) is always twice as big as some other quantity (represented by symbol y). Why can't you accept that information as given?

:confused:
because I concluded that and "not" directly give me that! .. my point isn't that I'm not accepting that, my point is that we get that not directly as "given" ! I mean none give me that in advance..
 

Ryan$

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That's so wrong.

Why do you argue about given information? You were told that some quantity (represented by symbol x) is always twice as big as some other quantity (represented by symbol y). Why can't you accept that information as given?

:confused:
"You were told that some" who told that? that's my point .. Yeah I concluded that from the equation after I did analysis but it wasn't directly given .. so still I consider it as "given" .. if so ..how is that true or reasonable? can you give me please a more real life analogy that imply the truth of that?
 
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