Branes hurting now.
Feb. 25th, 2007 11:52 pm![[personal profile]](https://www.dreamwidth.org/img/silk/identity/user.png)
0.999 = 1
Nope I didn't believe it either until I read this:
Algebraic proof:
Another kind of proof more easily adapts to other repeating decimals. When a number in decimal notation is multiplied by 10, the digits do not change but the decimal separator moves one place to the right. Thus 10 × 0.999… equals 9.999…, which is 9 more than the original number. To see this, consider that subtracting 0.999… from 9.999… can proceed digit by digit; in each of the digits after the decimal separator, the result is 9 − 9, which is 0. But trailing zeros do not change a number, so the difference is exactly 9. The final step uses algebra. Let the decimal number in question, 0.999…, be called c. Then 10c − c = 9. This is the same as 9c = 9. Dividing both sides by 9 completes the proof: c = 1.[1] Written mathematically,
c = 0.999...
10c = 9.999...
10c-c = 9.999...-0.999..
9c = 9
c = 1
The entire article can be found HERE
Nope I didn't believe it either until I read this:
Algebraic proof:
Another kind of proof more easily adapts to other repeating decimals. When a number in decimal notation is multiplied by 10, the digits do not change but the decimal separator moves one place to the right. Thus 10 × 0.999… equals 9.999…, which is 9 more than the original number. To see this, consider that subtracting 0.999… from 9.999… can proceed digit by digit; in each of the digits after the decimal separator, the result is 9 − 9, which is 0. But trailing zeros do not change a number, so the difference is exactly 9. The final step uses algebra. Let the decimal number in question, 0.999…, be called c. Then 10c − c = 9. This is the same as 9c = 9. Dividing both sides by 9 completes the proof: c = 1.[1] Written mathematically,
c = 0.999...
10c = 9.999...
10c-c = 9.999...-0.999..
9c = 9
c = 1
The entire article can be found HERE
no subject
Date: 2007-02-26 09:48 am (UTC)The thing I love about this, is that the algebraic part is completely logical....:D
no subject
Date: 2007-02-26 09:53 am (UTC)