So, I think i just proved math wrong.

[OOBradm]

http://pics.bbzzdd.com/users/OOBradm/calcwrong.JPG

I found this out today in class - If someone has a viable reason of why this doesnt prove math to be inconsistant, tell me please!

 

[bunker]

http://pics.bbzzdd.com/users/OOBradm/calcwrong.JPG

 

[Savij]

your calculator rounds

 

[GL]

doh!

 

[Xede]

dx/dt is not constant, so you're comparing dx/dt a minute from now with the instantaneous dx/dt right now. When volume is small, the sides grow quickly. When volume is large, the sides grow slowly because it takes only a very small growth in the sides of the cube to add a lot of volume.

 

[Savij]

and mine rounds the answer to 0.95379106343294581391175006166081

 

[OOBradm]

GL or Savij - either way, the answer is still not exactly 1. Which means there is a core inconsistancy in math.

 

[helpme]

Remember the theory of the limit.

 

[amoeba]

no its not a rounding issue. You have missed the point of calculus. dx/dt is constantly changing. Thus in that 1 minute, dx/dt is not always 1200cm/min. dx/dt is merely 1200cm/min at the point at which the cube is 20 by 20 by 20.

edit: dx/dt is merely 1cm/min.

 

[Savij]

doh, amoeba is correct about the dx/dt changing. I saw the obvious, calc rounding and stopped there

 

[GL]

Originally posted by: OOBradm
GL or Savij - either way, the answer is still not exactly 1. Which means there is a core inconsistancy in math.

You're right, there was a problem between the seat and calculator on my end I'm gonna erase my post above so as not to confuse anyone! Here's a hint at what I did by accident. Do 9200?3 and then forget about solving the rest of the question when the expected answer is close enough to that result

edit: argh no unicode characters...9200 root 3 instead of 3 root 9200.

 

[amoeba]

think of it this way.

try your experiment with x=1.

dv/dt =1200. dv/dt=3x^2 (dx/dt). 3x^2=3 when x=1. Thus dx/dt =400. Notice how dx/dt is different. infact dx/dt is different for every second, every milisecond, so forth until you reach limit as t->0. it is the rate of change of x at that particular time. as soon as time changes, dx/dt changes.

So no, you have not found any mathematical breakthroughs, you've just misunderstood calculus.

 

[SpazzyChicken]

dx/dt is constantly changing. Thus in that 1 minute, dx/dt is not always 1200cm/min. dx/dt is merely 1200cm/min at the point at which the cube is 20 by 20 by 20.

:beer: Bingo!

 

[rgwalt]

No, you did your calculations correct. However, you did not prove math wrong. You did show that you lack an understand of calculus and nonlinear functions, but that is OK... many people do.

While your rate of volume increase is constant, this does not mean the rate of increase in the length of a side of the cube (x) is constant. You used calculus to find the instantaneous rate of increase in x with increase in volume. So, when x=20, dx/dt = 1. However, what happens when x=21? dx/dt = 0.907. So, as V increases, x also increases, but dx/dt decreases.

When you computed "dx/dt" using your method, you made a large discrete step in time. You did not, in fact, compute dx/dt. You computed "delta x"/"delta t". dx/dt changed from a value of 1 to a value less than 1 over the course of your time step, hence the difference in the results.

R

 

[OOBradm]

wonderful. thanks guys for the explanation and i guess there wasnt a flaw in calculus, but a flaw in my knolwedge of it

 

[rgwalt]

Originally posted by: OOBradm
GL or Savij - either way, the answer is still not exactly 1. Which means there is a core inconsistancy in math.

No, there is no inconsistancy. You computed two different quantities. Your method did not compute dx/dt. It computed a discrete step over 1 second, not an instantaneous rate of change. You computed an approximation to dx/dt.

Ryan

 

[rgwalt]

Originally posted by: OOBradm
wonderful. thanks guys for the explanation and i guess there wasnt a flaw in calculus, but a flaw in my knolwedge of it

No problem, happy to help.

Ryan

 

[amoeba]

right, what rgwalt said is exactly right. when you calculate dx/dt by method one ( derivative). You are taking the derivative at that moment thus getting the instantaneous dx/dt.

 

[GermyBoy]

You are an idiot.

Why do people think that they can prove something wrong that has been scientifically proven to be correct for thousands of years?

It's like someone saying, "I just proved C wrong because my program doesn't compile. Check my program out!!!"

int main()
{
string xdflkjsdf;
int sdlkfjdsf;
float lksdjfljer = "hello";
boolean sldkjfdjl;
sldkjfdjl = sdlkfjdsf;
return "MOTHER_FVCKER_DOESNT_WORK";
}

The only problem is...people are stupid and don't ever check their own work, they just wanna be recognized for finding something cool out. Problem is, they don't realize that there is no rush because it's been proven for THOUSANDS OF YEARS already.

 

[Descartes]

Originally posted by: GermyBoy
You are an idiot.

Why do people think that they can prove something wrong that has been scientifically proven to be correct for thousands of years?

It's like someone saying, "I just proved C wrong because my program doesn't compile. Check my program out!!!"

int main()
{
string xdflkjsdf;
int sdlkfjdsf;
float lksdjfljer = "hello";
boolean sldkjfdjl;
sldkjfdjl = sdlkfjdsf;
return "MOTHER_FVCKER_DOESNT_WORK";
}

The only problem is...people are stupid and don't ever check their own work, they just wanna be recognized for finding something cool out. Problem is, they don't realize that there is no rush because it's been proven for THOUSANDS OF YEARS already.

Get the burr out of your arse. The guy was just wanting clarification on something, and he received it with thanks.

 

[amoeba]

Germy, don't jump on the guy man. I mean he did exhibit a bit of hubris in his statement, but its not wrong to question proven things. Thats how new things are discovered.

 

[rgwalt]

Originally posted by: GermyBoy
You are an idiot.

Why do people think that they can prove something wrong that has been scientifically proven to be correct for thousands of years?

It's like someone saying, "I just proved C wrong because my program doesn't compile. Check my program out!!!"

int main()
{
string xdflkjsdf;
int sdlkfjdsf;
float lksdjfljer = "hello";
boolean sldkjfdjl;
sldkjfdjl = sdlkfjdsf;
return "MOTHER_FVCKER_DOESNT_WORK";
}

The only problem is...people are stupid and don't ever check their own work, they just wanna be recognized for finding something cool out. Problem is, they don't realize that there is no rush because it's been proven for THOUSANDS OF YEARS already.

Easy there Tex, try reading the rest of the thread before replying.

R

 

[waggy]

Originally posted by: amoeba
Germy, don't jump on the guy man. I mean he did exhibit a bit of hubris in his statement, but its not wrong to question proven things. Thats how new things are discovered.

while germy was being an asshole. he is correct.

 

[amoeba]

Originally posted by: waggy

Originally posted by: amoeba
Germy, don't jump on the guy man. I mean he did exhibit a bit of hubris in his statement, but its not wrong to question proven things. Thats how new things are discovered.

while germy was being an asshole. he is correct.

If the OP started arguing his position even after proof was offered, I would agree. However, the OP cordially accepted the help and lets leave it at that. No reason to attack him.


This by the way reminds of me the 1=.99999~ thread for some reason.

 

[Spencer278]

Originally posted by: GermyBoy
You are an idiot.

Why do people think that they can prove something wrong that has been scientifically proven to be correct for thousands of years?

It's like someone saying, "I just proved C wrong because my program doesn't compile. Check my program out!!!"

int main()
{
string xdflkjsdf;
int sdlkfjdsf;
float lksdjfljer = "hello";
boolean sldkjfdjl;
sldkjfdjl = sdlkfjdsf;
return "MOTHER_FVCKER_DOESNT_WORK";
}

The only problem is...people are stupid and don't ever check their own work, they just wanna be recognized for finding something cool out. Problem is, they don't realize that there is no rush because it's been proven for THOUSANDS OF YEARS already.

I think the problem is that either string or boolean are valid c types.