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Post by Guest »

MKJ wrote:toxic, a question for you

0 x infinity = what ?
its an indeterminant form. just like 1^infinity, 0/0 and infinity/infinity. If you take a limit as x -> infinity then it will depend on the example. A good example of 0/0 (ie 0*inf depending how you write it) would be the limit of sin(x)/x as x -> 0.
l0g1c
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Joined: Tue May 07, 2002 7:00 am

Post by l0g1c »

ToxicBug wrote:
MKJ wrote:toxic, a question for you

0 x infinity = what ?
its an indeterminant form. just like 1^infinity, 0/0 and infinity/infinity. If you take a limit as x -> infinity then it will depend on the example. A good example of 0/0 (ie 0*inf depending how you write it) would be the limit of sin(x)/x as x -> 0.
Indeterminate :icon26:
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duffman91
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Joined: Thu Jan 25, 2001 8:00 am

Post by duffman91 »

ToxicBug wrote:
The point is that you can't count to infinity, because no matter how fast you count, you will be counting forever and ever :shrug:

In calculus you don't "use" infinity, when you find a limit for example you define some number that approaches infinity, but isn't "infinity".
Trust me, you don't have to tell me that. I'm obviously refering to limits, euler sums, and integrals.
Guest

Post by Guest »

duffman91 wrote:
ToxicBug wrote:
The point is that you can't count to infinity, because no matter how fast you count, you will be counting forever and ever :shrug:

In calculus you don't "use" infinity, when you find a limit for example you define some number that approaches infinity, but isn't "infinity".
Trust me, you don't have to tell me that. I'm obviously refering to limits, euler sums, and integrals.
I know that you're an engineer :icon14:
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MKJ
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Joined: Fri Nov 24, 2000 8:00 am

Post by MKJ »

ToxicBug wrote:
MKJ wrote:toxic, a question for you

0 x infinity = what ?
its an indeterminant form. just like 1^infinity, 0/0 and infinity/infinity. If you take a limit as x -> infinity then it will depend on the example. A good example of 0/0 (ie 0*inf depending how you write it) would be the limit of sin(x)/x as x -> 0.
gg :smirk:
+1 smarts
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Guest

Post by Guest »

MKJ wrote:
ToxicBug wrote:
MKJ wrote:toxic, a question for you

0 x infinity = what ?
its an indeterminant form. just like 1^infinity, 0/0 and infinity/infinity. If you take a limit as x -> infinity then it will depend on the example. A good example of 0/0 (ie 0*inf depending how you write it) would be the limit of sin(x)/x as x -> 0.
gg :smirk:
+1 smarts
By the way, if you would like to know the limit of sin(x)/x as x -> 0, you can find it by using L'Hopital's rule, ie when the limit f(x)/g(x) is in a 0/0 or inf/inf form, it equals to f'(x)/g'(x).

f'(x) = d/dx sin(x) = cos(x)
g'(x) = d/dx x = 1

Therefore the limit of sin(x)/x as x -> 0
= lim x->0 cos(x)/1
= cos(0)/1
= 1/1
= 1

So the limit of sin(x)/x as x -> 0 is 1.
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