Maths can be weird....
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to summarise, graph of 1/x only shows limit is not defined at x=0. Remeber limit is something close to 0 but not 0.
You need to prove 1/x is undefined at x=0, not at x approachs 0+ or 0-.
And you need to prove for all cases 1/0=undefined, not just for one example.
If you want to give counterexample,
show 1/0=defined for one case will do. -
you have to first admit you are wrong(cos you are) then i prove it to you. otherwise it is just a waste of my time.Originally posted by hisoka:go dig then say bah. btw i will ask you to prove every thing you do hor. including all x+ y and x/y and what not.
it'll be fun to watch if nothign else
why no need to prove that definition no need to prove? pls proof that. -
i am not wrong until you can prove it to me remember??Originally posted by Gasfene:you have to first admit you are wrong(cos you are) then i prove it to you. otherwise it is just a waste of my time. -
yup i know u will say that. anyway 0=0 has nothing to do with this question remember?Originally posted by hisoka:i am not wrong until you can prove it to me remember?? -
Damn, I've been trying to remember the delta-epsilon proof for lim 1/x as x --> 0.
Anyone can help? -
not sure i also forgot the all arguments you and i put out le. the 0=0 was something you put out to disprove me or somethign i think. there fore since you were using it to disprove, i had to call you to prove that.Originally posted by Gasfene:yup i know u will say that. anyway 0=0 has nothing to do with this question remember?
hmm oh yeah i think should be asking you to prove 0*1 = 0 isit??
too fun until forgot the thing le paiseh -
Originally posted by CoolMyth:Damn, I've been trying to remember the delta-epsilon proof for lim 1/x as x --> 0.
Anyone can help?
ask gasfene since he calims to be an expert in maths.
then i'll have fun askign him to prove everythign he uses -
Never mind lah, just stick to the logic proof.
I never really liked calculus and analysis anyway. -
doesnt matter. This 0*1=0 thing has been proven by someone already. I wont go prove it to someone who tries to be funny when he has nothing more to argue about.
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Coolmyth dude.. u saw my question right? Can help me uncover one of life's greatest mysteriesOriginally posted by CoolMyth:Damn, I've been trying to remember the delta-epsilon proof for lim 1/x as x --> 0.
Anyone can help? 
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Originally posted by Gasfene:doesnt matter. This 0*1=0 thing has been proven by someone already. I wont go prove it to someone who tries to be funny when he has nothing more to argue about.
not i nothing to argue but i lazy to go thru logic. its rather troublesome and with some one askign for provees of everything its hard and troublesome to argue or did you not notice that?
0*1 proven by some one doesn't mean its proven. it only means its proven to the point that no one has managed to disprove the prove -
Damn, I've been trying to remember the delta-epsilon proof for lim 1/x as x --> 0.
Anyone can help?
This one the answer for this limit is obiouvly lim x->0=infinity.
so we prove that it is always bigger than a constant k for any delta.
Given any K>0, we take delta=1/k. then 0=>1/x>k
I didnt claim to be a maths expert ffs. -
This one I think I remember.Originally posted by Gasfene:doesnt matter. This 0*1=0 thing has been proven by someone already. I wont go prove it to someone who tries to be funny when he has nothing more to argue about.
0*1 = 0
Basically, it's 0*x = 0 for x = 1 right? So showing 0*x = 0 is the same as showing 0*1 = 0, right?
Using real field axioms, you can show that if x + y = x, then y = 0.
Then,
0*x + 0*x = (0 + 0)*x by distribution property = 0*x by the axiom that there exist an element 0 such that x + 0 = x
So 0*x = 0. That shall be it. -
nay you just calimed that we need a maths expert to counter your maths???Originally posted by Gasfene:Damn, I've been trying to remember the delta-epsilon proof for lim 1/x as x --> 0.
Anyone can help?
This one the answer for this limit is obiouvly lim x->0=infinity.
so we prove that it is always bigger than a constant k for any delta.
Given any K>0, we take delta=1/k. then 0=>1/x>k
I didnt claim to be a maths expert ffs. -
Ah yes, that's it. Thanks.Originally posted by Gasfene:Damn, I've been trying to remember the delta-epsilon proof for lim 1/x as x --> 0.
Anyone can help?
This one the answer for this limit is obiouvly lim x->0=infinity.
so we prove that it is always bigger than a constant k for any delta.
Given any K>0, we take delta=1/k. then 0=>1/x>k
I didnt claim to be a maths expert ffs. -
ya it has not yet been disproved. Why dont you go disprove it then?Originally posted by hisoka:
not i nothing to argue but i lazy to go thru logic. its rather troublesome and with some one askign for provees of everything its hard and troublesome to argue or did you not notice that?
0*1 proven by some one doesn't mean its proven. it only means its proven to the point that no one has managed to disprove the prove
haha want me to tell you the prove first right? lol -
go ahead lor. i'm just bored it would entertain me i guess.Originally posted by Gasfene:ya it has not yet been disproved. Why dont you go disprove it then?
haha want me to tell you the prove first right? lol
i'm not here cos i feel a need to prove somethign is right or even if my way of proving is correct. -
Ah, the wonders of google. Thank you Dr Maths. Now I understand why 1/0 is undefined.
http://mathforum.org/library/drmath/view/53336.html
There's always something to be learned in maths. -
i love math
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hi bear.Originally posted by the Bear:i love math -
same as my answer:pOriginally posted by CoolMyth:Ah, the wonders of google. Thank you Dr Maths. Now I understand why 1/0 is undefined.
http://mathforum.org/library/drmath/view/53336.html
There's always something to be learned in maths.
anyway, i dont think there is a calculus proof for this. -
Originally posted by Gasfene:same as my answer:p
anyway, i dont think there is a calculus proof for this.
I realised it's not as easy as it sounds really.
No point thinking about what I can't do. -
i will try to dig notes and see if i can understand the proof again.Originally posted by hisoka:go ahead lor. i'm just bored it would entertain me i guess.
i'm not here cos i feel a need to prove somethign is right or even if my way of proving is correct.
Anyway for obvious question like 1*0=0, the first step is always to suppse 1*0 not equal to 0 then proof by contradiction. -
Nobody appreciates my algebra proof.
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interesting. but i just realised something. why do we need to prove the thign when the basis for our proofs are definitions which are unprovedOriginally posted by CoolMyth:
I realised it's not as easy as it sounds really.
No point thinking about what I can't do.
this came up witht he arguments i made later.
no need to reply thx