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Mathematical error 1=0.9 repeating

User Thread
 32yrs • M •
A CTL of 1 means that Jacker_Jones is a contributing member of Captain Cynic.
Mathematical error 1=0.9 repeating
let x=0.9(repeating)
10x=9.9(repeating)
10x-x=9.9(repeating)-0.9(repeating)
9x=9
x=1
therefore 1 is actually 0.9(repeating)

repeating is the line above meaning goes on forever

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"I love to see people struggling for their purpose in life..."
 31yrs • M •
A CTL of 1 means that St. Jimmy is a contributing member of Captain Cynic.
right
it's not actually an error, rather, .9(repeating) is so close to 1 that there are no numbers in between .9(repeating) and one, but this is impossible, and therefore .9(repeating) is equal to 1
as you proved.

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"He who does not question is lost."
 37yrs • M •
A CTL of 1 means that heyjme1 is a contributing member of Captain Cynic.
The' error' rises in the (in)ability of maths to understand the concept of infinity and this is up to the user.

If x = 0.999(recurinng); then when one really multiplies this by 10 you translate the whole thing across. So for example if x = 0.9999 then 10x = 9.999 and thus one 'loses' 0.0009. Now if you take recurring to mean infinity, this of course does not happen when you multiply by 10 so 0.999999recurring becomes effectively 1 by the user, in the first instance. Really, then, the outcome is up to the belief of the user. This assumption appears in the second line of these equations.

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""No words""
 31yrs • M •
A CTL of 1 means that lastresort is a contributing member of Captain Cynic.
math is just a language used for mathematicians to describe size, quantity, and order... there is no "one" answer to any math problem. math is always evolving as we need to describe more things, think of calculus for that matter.... newton needed to make a language so he could describe his laws to the world....

on the math thought, do you agree or disagree with this formula proving 1=2...

a = b
a^2 = a*b
a^2-b^2 = a*b-b^2
(a+b)(a-b) = b(a-b)
(a+b) = b
a+a = a
2a = a
2 = 1



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 32yrs • M •
A CTL of 1 means that eliasan is a contributing member of Captain Cynic.
run that by ur math teachers and see what they think.

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"Fear nothing for fear is the mind killer."
 31yrs • M •
A CTL of 1 means that lastresort is a contributing member of Captain Cynic.
i know the answer.. im seeing if anyone else can get it.

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 31yrs • M
A CTL of 1 means that awakendwraith is a contributing member of Captain Cynic.
10x-x=9.9(repeating)-0.9(repeating)
9x=9

10(.9)=9
9 - .9= 8.1
9.9 - .9= 9
so 8.1=9... right?

10 times 90% is 9.

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"Why cry for those that often cry? Instead, help them smile, and smile for those that smile."
 31yrs • M •
A CTL of 1 means that sleepingwraith is a contributing member of Captain Cynic.
.
.

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"Life is such sweet sorrow."
[  Edited by sleepingwraith at   ]
 32yrs • M •
A CTL of 1 means that Jacker_Jones is a contributing member of Captain Cynic.
no it works out. Anything devided by itself is equal to 1. for instence if (a-b) is equal to three well then 3/3 is equal to 1. So it cancels out on both sides.

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"I love to see people struggling for their purpose in life..."
 33yrs • M •
DrumMajor is new to Captain Cynic and has less than 15 posts. New members have certain restrictions and must fill in CAPTCHAs to use various parts of the site.
a = b
a^2 = a*b
a^2-b^2 = a*b-b^2
(a+b)(a-b) = b(a-b)
(a+b) = b
a+a = a
2a = a
2 = 1

In line 4 both sides of the equation have the factor (a-b). Since a=b a-b=0. The fifth liine may be rewritten as (a+b)(a-b)/(a-b) = b(a-b)/(a-b). Since a-b=o what we have is a classic case of division by zero, or the question "How many times does zero go into..." since no matter how many times you add a factor of zero you remain at zero zero goes into any number an infinite amount of times (it never reaches its goal). In other words the final line should read 2/0=1/0, infinity equals infinity, a true statement.

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 33yrs • M •
DrumMajor is new to Captain Cynic and has less than 15 posts. New members have certain restrictions and must fill in CAPTCHAs to use various parts of the site.
let x=0.9(repeating)
10x=9.9(repeating)
10x-x=9.9(repeating)-0.9(repeating)
9x=9
x=1
therefore 1 is actually 0.9(repeating)

Now let X equal a finite number: .99
10x=9.9
10x-x=9.9-.99
9x=8.91
x=.99

Let x=.99999
10x-9.9999
10x-x=9.9999-.99999
9x=8.99991

This patern (an 8 followed by (n-1) 9s where n is the amount of digits in x followed by a 1) continues no matter how many digits X goes out to. You should think of .9(repeating) times 10 not as 9.9(repeating) but as 9.9(repating)0, an infinite amount of nines followed by a zero. This way the zero in that number is always by the final nine in .9(repeating) and when you subtract them you will gett 8.9(infinity-1 times)1 which divided by 9 yields .9(repeating)

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 31yrs • M •
A CTL of 1 means that lastresort is a contributing member of Captain Cynic.
heyo! we have a winner!... sort of. when you divide a number by 0, lets say 3/0... you're asking how many groups of 0 can go into 3 and that answer does not exist, it is not infinity... this is because if it was infinity and you put a number as an answer then check it... lets put 4... you get 4*0=3 which is by all means false, this happens with all numbers you put in, therefore you have no answer.

HOWEVER

what if you do 0/0, THEN you get infinity. because any number times 0 = 0. so, what if

a=b=0
a^2 = a*b
a^2-b^2 = a*b-b^2
(a+b)(a-b) = b(a-b)
(a+b) = b
a+a = a
2a = a
2 = 1


??

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 43yrs • M •
A CTL of 1 means that tommybc98 is a contributing member of Captain Cynic.
Drummajor, infinity is not a number: the concept of infinity-1 times is not valid in the context in which is is used.
Jacker_Jones, have you worked with limits and open intervals in calculus yet?

lim (x) = 1
x -> infinity

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"Live a good, honorable life. Then when you get older and think back, you'll enjoy it a second time"
[  Edited by tommybc98 at   ]
 32yrs • M •
A CTL of 1 means that Jacker_Jones is a contributing member of Captain Cynic.
No i haven't had the pleasure perhaps in the future

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"I love to see people struggling for their purpose in life..."
 31yrs • M •
A CTL of 1 means that Ancient is a contributing member of Captain Cynic.
You still can't devide by zero as you assume to in this problem.

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"Dark and silent and complete."
Mathematical error 1=0.9 repeating
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