0.9999 . . . = 1? It sure seems so.

I reached my level of incompetence in math at..............

 
That is a 5. You are just looking at the back of the number. But the back of a 5 is still a 5. My son can prove it.

I think you should get some help after school from the spacial orientation instructor.

Its called "spacial ed".
 
I went through Electrical Engineering using a slide rule, so 0.99999999999........ was definitely = 1.
 
Those infinitely wide slide rules are a real pain to put in the backpack, aren't they. :)
 
I think Spock had it right. The number of nines after the decimal is just a measure of acceptable margin of error. "She's a 9 out of 10." Hell, I'll accept that. No need to go looking for a 9.9. I couldn't afford her anyway. If someone owes you a hundred bucks and they only paid you $99.99 you would probably be ok with that. If not just pull a penny out of the cup at the qiuckiemart and get on with life. If you won a million dollar settlement and got $999,999 after lawyers fees you would be even more ok with that. You need a lot more 9s to shoot a spacecraft to Mars than the moon. Until we invent weights and measures instruments that count individual molecules and wavelengths of light we'll always be dealing with the 9s. 1 is only in theory but practice is always varying numbers of 9s. I've known far to many people too willing to accept a bunch of 7s and 8s in there at the end as well.
 
In calculus, 0.999999... = 1 just means that the sequence of numbers 0.9, 0.99, 0.999, 0.9999,... (i.e., 9/10, 99/100, 999/1000, 9999/100000,...) converges to 1. I.e., you can approximate the number 1 as closely as you wish by means of fractions of the form 0.999...9. Unless you are interested in mathematics, it's not worth worrying about it.
 
Mongo said:
Bacon.
Click to expand...

That !

And if the kids is not to old or to smart you counter with the rice & chess board scenario ,
ask them to put 1 rice grain on the first square 2 on the second , then 4 , 8 , 16 ,,,,

that will teach them to count on their fingers like normal people do without those
electronic calculator thingamajigs .


1234,,,,,:D
 
sheepdog229 said:
That picture is wrong. should be 3.14159265
Click to expand...


May I direct you to the word incompetence? :D


Not to change the subject or anything, but there is a product that we all use which can not be purchased as a single unit. In other words, you can not
the purchase the base quantity of this item for it's listed price.
 
Last edited:
UffDa said:
May I direct you to the word incompetence? :D


Not to change the subject or anything, but there is a product that we all use which can not be purchased as a single unit. In other words, you can not
the purchase the base quantity of this item for it's listed price.
Click to expand...

Maybe I have had too much to drink but I don't have a clue as to what you mean?!?!
 
sheepdog229 said:
Maybe I have had too much to drink but I don't have a clue as to what you mean?!?!
Click to expand...

Gasoline. You can not purchase a single unit of gasoline for the listed price in the United States. There may be exceptions, but I don't know of any.
 
UffDa said:
Gasoline. You can not purchase a single unit of gasoline for the listed price in the United States. There may be exceptions, but I don't know of any.
Click to expand...

Huh? I have a one-gallon gas can; I've never had any problem filling it up.
Confused-Cat.gif
 
If that hurt your brain than think about this; 2+2=1 mod3. Modular arithmetic. Has something to do with rings and fields but its been a while since i gradumacated.
 
Cougar Allen said:
Huh? I have a one-gallon gas can; I've never had any problem filling it up.
Confused-Cat.gif
Click to expand...

It's not a difficult concept. Let's say that 1 gallon of gas costs $3.29 9/10. Since there is no 9/10 cent coin, you have to either buy a little more or a little less, but you can not buy exactly 1 gallon.
 
There's an error in the mathematics. I'm going to write this out 2 different ways to demonstrate.
For convention (and convenience), infinity will be represented by "oo".


x = 0.9999... (oo)
10x = 9.9999... (oo)
This is where the error is. By multiplying the number times 10, he shifted the decimal point one position to the right. So there aren't (oo) nines to the right of the decimal point, there's (oo-1) nines to the right of the decimal point.

10x - x = 9.9999...(00-1) - 0.9999...(oo)
9x = 9 - .0(oo-1)....9
x = 1-.0(oo-1)...1 = 0.9999...

**************************************************
The second method is a little easier to understand. .9999... is written as 1-1/oo.

x = 1-1/oo
10x = 10 (1 - 1/oo) = 10 - 10/oo
10x - x = 10 - 10/oo - (1 - 1/oo) = 9 - 9/oo
9x = 9 - 9/oo
x = 1 - 1/oo = .9999...

EDIT: Wait till the kid hits calculus 2 (convergent and divergent infinite series). It's all the cr@p I talked about above. If your brains aren't leaking out your ears by then, they will be.
 
Last edited:
Gollnick said:
In algebra, .999999... = 1
But, .99999... != 1.0

In calculus, .999999... != 1
In calculus, there is this thing called a differential (often written as dx) which is the smallest possible difference. So, .999999... = 1 - dx.
Click to expand...

+1 Yup.
 
Seanifred said:
I am a grad student in physical chemistry and laser and biophysics. my family hates me
Click to expand...

You should try theoretical physics + laser physics + modern optics + solid state physics + quantum mechanics. Add a little dash of national security ... even my mother won't talk to me.

If she were still alive.
 
You must log in or register to reply here.
Back
Top