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#1 2009-10-20 20:36:32

saundo
Member
Registered: 2009-10-20
Posts: 8

proof that 2=2.82 thus that algebra has a huge fault

i have proven not that 1=2 but that 2=3.41 i am only 16 but im pretty sure there are no faults in this. what i did and expalnations on how are written below
x=2 y=2
x=y
x^2=y+x
√(x^2 )=√(y)+(x)
x=1.41+x
2=1.41+2
2=3.14
line1  x=2 y=2
line 2 therefore x=y
line 3 add x to both sides( since x=2 and 2+2 Is  the same as 2^2 it become x^2)
line 4 square root both sides of the equation
line 5 we are left with x=1.41+x because √2 is 1.41 to 2 decimal places
line 6 substitute the pro-numeral x with the its value (2) leaves us with 2=1.41+2
line 7 the answer is 2=3.41
find any faults now?

Last edited by saundo (2009-10-21 00:44:46)

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#2 2009-10-20 21:19:53

dannyv
Member
Registered: 2007-09-20
Posts: 34

Re: proof that 2=2.82 thus that algebra has a huge fault

the problem is between line4 and 5. You cannot distribute the square root, i mean,

To my knowledge there is no way to decompose a square root

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#3 2009-10-20 23:26:06

MathsIsFun
Administrator
Registered: 2005-01-21
Posts: 7,631

Re: proof that 2=2.82 thus that algebra has a huge fault

I removed a rude comment

Nice try, saundo, but Algebra still wins smile


"The physicists defer only to mathematicians, and the mathematicians defer only to God ..."  - Leon M. Lederman

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#4 2009-10-21 00:34:18

saundo
Member
Registered: 2009-10-20
Posts: 8

Re: proof that 2=2.82 thus that algebra has a huge fault

dannyv wrote:

the problem is between line4 and 5. You cannot distribute the square root, i mean,

To my knowledge there is no way to decompose a square root

for some reason the brackets did not come up properly

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#5 2009-11-22 03:51:16

simplyjasper
Member
Registered: 2009-11-15
Posts: 24

Re: proof that 2=2.82 thus that algebra has a huge fault

3rd line itself is wrong...
If y = x,

x + y = 2x or 2y not x^2

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#6 2009-11-22 19:39:28

bobbym
Administrator
From: Bumpkinland
Registered: 2009-04-12
Posts: 107,680

Re: proof that 2=2.82 thus that algebra has a huge fault

Hi;

For x=2 and y=2 as he states in line 1:

You can say x + y = x^2.


In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.

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#7 2010-05-17 08:32:52

DaveRobinsonUK
Member
Registered: 2010-04-24
Posts: 123

Re: proof that 2=2.82 thus that algebra has a huge fault

Hi Saundo

Are you using a calculator? If so are you pressing the equals sign when you add x+y or entering x then add then y
then the sqrt.

I get 1.4142136, which is the approximation of the sqrt(2) and when I then press = I get 3.4142136

The reason for this is that calculators and programming languages evaluate certain operations before others
usually following the BIDMAS rules. Since SQRT() is a division operation it would be evaluated first on the
associated number, which is 2.

If you have a bracket function, you should get 2. The correct answer should be (+/-2)


Can feel it coming together.. Slowly but Surely smile

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#8 2010-10-26 14:41:31

thewordalive
Member
Registered: 2010-09-27
Posts: 4

Re: proof that 2=2.82 thus that algebra has a huge fault

MathsIsFun wrote:

I removed a rude comment

Algebra still wins smile

algebra wins, but geometry pwns >:]

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