LOL, made my day.

LOL it works i was talkin about, forgetting that 9/9 = 1, cuz u can also get .999...

I'm no math mathematician, but how does doing long division incorrectly prove anything?

.9r does not equal 1.... Im aware of the type of book this is found in... but for decades they told kids 22/7 = pi

This post was edited by FatZero on Apr 26 2010 10:44pm

trolltrolltroll

22/7 is actually a pretty accurate designation for pi. it's simply just an easy way to calculate pi without having to actually remember all the digits. it was just for simplicity's sake

either you get it or you don't, but .999r = 1.0. people are saying, well they're obviously not the same number so how are they the same? one would say this if they have not had any type of basic calculus education. for example, let us take the following graph of f(x) = 1/x (for those of you that don't know, http://www.revisioncentre.co.uk/gcse/maths/1overx.gif)

now, let's say we plug in a number for x. but what if we plug in bigger numbers? When X = 5, Y = .2. X = 500, Y = .002. What if i'm ridiculous and say, well what if I have an input of X = 500000000000? Your Y is going to be tiny. Y = 0.000000000002 to be exact. This is where the concept of Limits come into play; as you increase your input X, it approaches 0 but is still an infinitely small value, our Y result approaches 0, but never hits it. If we evaluate the limit of this function, Y = 1/x, as X approaches infinity, we then say that Y approaches 0. This is the definition of a limit. Y never actually hits 0, that's not possible from the basis of our function. However, when one looks at the Limit of the function as X approaches infinity, our final input Y is equal to 0.

Let's start over. Let's say we replace our function with Y = 1 - (1/x). So, as before we plug in numbers and we evaluate the function. When X = 5, Y = .8. When X = 500, Y = 0.998. See a trend here? As people have said before, even if you DO plug in large values for X, the function itself will never approach 1, because it will just keep getting more and more 9's in the decimal .9999999r. However, what if your X value is infinity? The value of your 1/x part will be infinitely small, such that your final value, will "literally" be Y = .9999999forever. HOWEVER, when we observe this in a "theoretical" standpoint, the fact that you are plugging X = infinity simply wipes out the 1/x term altogether; the limit of this 1/x term as x approaches infinity is 0. Therefore, based on this logic, when X approaches infinity, Y = 1.

But didn't I say before that Y = .9999r? Then why did I just say that Y = 1?

Because they are the same thing.

1/3 as a fraction x3=1
1/3 as a decimal .3 repeating x3 does not = 1

My God!

1 (divided by) 3 = 0.3(3) <----- it's a PERIODIC number!
Which means, 0.3(3) * 3 = 1

Proof:

1/3 is just a different representation of the number 0.3(3). Sooo... if:

1/3 * 3 = 1
then the following is also true:
0.3(3) * 3 = 1

You're questioning one of the most fundamental rules in math (too bad I don't know it's english name, but I remember It's taught in 1st or 2nd grade at school.). Stop, because some ppl are making ridiculous statements! There's no error in math I assure you. It's like one of those ridiculous proofs that 1 equals 2. Rofl

X = 0.9999999(recurring)

10X = 9.999999999(recuring)
10X - X = 9X
9X = 9
X = 1

lmk

you guys don't understand the fact that these numbers are recurring. 0.99999... doesn't stop, it's continues with 9s all the way. if it was 0.99999 without the recurring part, then it wouldn't be 1. but it's simple a law in maths that 0.9999999(9) = 1