#is this proof valid or am i stupid

50 messages · Page 1 of 1 (latest)

tacit timberBOT
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lethal knot
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$\lim_{x\to 0}(fg)(x)=\infty$ since it's $\frac{1}{x^2}$ for $x\neq 0$

light geodeBOT
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Omegabet_

karmic cedar
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oh i guess that makes sense

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what would be another example to counterrpoof this?

lethal knot
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I mean, $f(x)=\begin{cases}7&x\neq 0\1&x=0\end{cases}$ isnt continuous at $0$

light geodeBOT
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Omegabet_

lethal knot
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you can easily find a g such that (fg)(x)=1 for all x in R and isnt continuous at 1

karmic cedar
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and the new f

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what would be the fg

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im not sure how to multiply piecewise functions

lethal knot
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Clearly it'd be 7/x for x not 0, and 0 for x=0

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You do it pointwise

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For x!=0, (fg)(x)=7 * 1/x

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For x =0, (fg)(0)=1*0=0

karmic cedar
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ah okay i get it

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but then fg is also not continuous

lethal knot
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Yep

karmic cedar
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so the claim is true?

lethal knot
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No

karmic cedar
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but to proof the claim being wrong i need to show its continuous

karmic cedar
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oh

lethal knot
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No

karmic cedar
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i have to change g(X)

lethal knot
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Yes...

karmic cedar
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ok so if i just make g(X) the opposite

lethal knot
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Explicitly write g

karmic cedar
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so for x=0 7 and wiseversa

lethal knot
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Opposite isn't well defined

karmic cedar
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wdym well define

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oh

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yh

lethal knot
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Opposite doesn't have a meaning here

karmic cedar
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g(X) 1 x=/=0

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and 7 =0

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then H(X) would be 7 everywhere

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and therefore be continuous

lethal knot
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Yes

karmic cedar
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ok thanks alot

karmic cedar
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-close

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gentle tuskBOT
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Unable to parse the channel name

karmic cedar
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!close

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,close

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light geodeBOT
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cerulean wadi
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