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October 01, 2025, 01:48:23 am

Author Topic: horizontal asymptotes can be crossed...  (Read 3454 times)  Share 

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taiga

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Re: horizontal asymptotes can be crossed...
« Reply #15 on: September 24, 2010, 12:58:22 am »
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The precise definition of a horizontal asymptote is the following:

Let be defined on then means for every there exists a corresponding number such that if then . Likewise let be defined on then means for every there is a corresponding such that if then .

is the horizontal asymptote.

Thus horizontal asymptote can certainly be crossed.



Exercise for those interested: Using the same logic as above, can you formalise vertical asymptotes?

but in all honestly no one read that :P
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8039

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Re: horizontal asymptotes can be crossed...
« Reply #16 on: September 24, 2010, 01:24:08 am »
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The precise definition of a horizontal asymptote is the following:

Let be defined on then means for every there exists a corresponding number such that if then . Likewise let be defined on then means for every there is a corresponding such that if then .

is the horizontal asymptote.

Thus horizontal asymptote can certainly be crossed.



Exercise for those interested: Using the same logic as above, can you formalise vertical asymptotes?

but in all honestly no one read that :P

I read it but in the same way I read Shakespeare... not knowing wtf is going on

TrueTears

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Re: horizontal asymptotes can be crossed...
« Reply #17 on: September 24, 2010, 01:27:10 am »
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the mathematical language used is within methods boundaries and i bet if i explained it a bit more using english everyone wud understand, it's actually very very intuitive except i cbf lol.. maybe kamil or someone can translate into english for ya guys
« Last Edit: September 24, 2010, 01:29:53 am by TrueTears »
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8039

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Re: horizontal asymptotes can be crossed...
« Reply #18 on: September 24, 2010, 01:33:38 am »
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the mathematical language used is within methods boundaries and i bet if i explained it a bit more using english everyone wud understand, it's actually very very intuitive except i cbf lol..

Well I had enough trouble understanding limits in the Essential book so that explains my confusion. I kinda get it it till x>N and the absolute value thing thingo. And how it proves that the horizontal line can be crossed

Martoman

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Re: horizontal asymptotes can be crossed...
« Reply #19 on: September 24, 2010, 01:37:46 am »
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Well TT sir, i prefer good old english.

When you have something like if you let y = 0 then you can have either

or

For the first one, this cannot ever happen, but it *can* for the second. It is asymptotic for extremely small values of x because so it approaches zero as x becomes extremely small.

But for things like

if you let y = 7 then you have the unsavoury situation of implying and o noooooo the universe has sufficiently exploded. ie proof by contradiction.

This is why you cannot cross vertical ones. You will invariably end up with some ridiculous statement like 1= 9 or a = b where a doesn't = b....  :uglystupid2:

For the question
On that same topic, I wonder whether the graph has an asymptote

e^-x = 0, sin(x) = 0

x has a solution at x = 0, y = 0 so it does cross, yet behaves asymptotically because as you tend towards infinity, so it appraoches 0
« Last Edit: September 24, 2010, 01:39:45 am by Martoman »
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TrueTears

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Re: horizontal asymptotes can be crossed...
« Reply #20 on: September 24, 2010, 01:43:53 am »
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yer in vce maths u dont have to be so formal lol (its coz im reading a few books on elementary topology and analysis so i'm being a formal bastard with all the maths i do nowadays LOL) but once you go past vce, being formal with these asymptotes are great! You can do wonderful proofs and stuff~
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8039

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Re: horizontal asymptotes can be crossed...
« Reply #21 on: September 24, 2010, 01:52:11 am »
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Well TT sir, i prefer good old english.

When you have something like if you let y = 0 then you can have either

or

For the first one, this cannot ever happen, but it *can* for the second. It is asymptotic for extremely small values of x because so it approaches zero as x becomes extremely small.

But for things like

if you let y = 7 then you have the unsavoury situation of implying and o noooooo the universe has sufficiently exploded. ie proof by contradiction.

This is why you cannot cross vertical ones. You will invariably end up with some ridiculous statement like 1= 9 or a = b where a doesn't = b....  :uglystupid2:

For the question
On that same topic, I wonder whether the graph has an asymptote

e^-x = 0, sin(x) = 0

x has a solution at x = 0, y = 0 so it does cross, yet behaves asymptotically because as you tend towards infinity, so it appraoches 0

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/0

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Re: horizontal asymptotes can be crossed...
« Reply #22 on: September 24, 2010, 03:33:10 am »
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The precise definition of a horizontal asymptote is the following:

Let be defined on then means for every there exists a corresponding number such that if then . Likewise let be defined on then means for every there is a corresponding such that if then .

is the horizontal asymptote.

Thus horizontal asymptote can certainly be crossed.



Exercise for those interested: Using the same logic as above, can you formalise vertical asymptotes?

Reading that hurt my head -_-

lol that's basically all of Analysis

TrueTears

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Re: horizontal asymptotes can be crossed...
« Reply #23 on: September 24, 2010, 03:35:36 am »
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analysis!!!!!
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Martoman

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Re: horizontal asymptotes can be crossed...
« Reply #24 on: September 24, 2010, 05:02:24 am »
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2009: Math methods: 50, Psychology: 44
2010: chem 47, further 48, Spesh 49 fml seriously and other yr 11 subs.
2011: Holidaying, screw school.
No. Not azn.
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