Math is useless

I will now prove that math is completely useless by proving that all numbers are the same. Virtual Cookie to the first that notices the fallacy.

Ok, so we have our numbers a and b.

a + b = t

we multiply with a - b on both sides

(a + b)(a - b) = t(a - b)

Now, as we all know, (a + b)(a - b) = a^2 - b^2 so then we get

a^2 - b^2 = ta - tb

which means that

a^2 - ta = b^2 - tb

Now, we'll add t^2/4 to both sides, giving us

a^2 - ta + t^2/4 = b^2 - tb + t^2/4

and as we also know, (a - b)^2 = a^2 - 2ab + b^2, which if we use in reverse gives us

(a - t/2)^2 = (b - t/2)^2

then we take the square root of both sides

a - t/2 = b - t/2

therefore

a = b

So therefore we know that all numbers are the same and that math is completely irrellevant.

Phail at the square root.

The things that are to be squared are the negatives of each other.

ie (a-t/2) = -(b-t/2)

>>1
http://en.wikipedia.org/wiki/Invalid_proof
(the list doesn't have yours specifically, but it has ones that use the same fallacy)

I don't get it, you note yourself that the proof is wrong, yet you still assert that mathematics is useless.

I guess you're just trollin', they hatin'

a=b

a+b=t

so 2a=t

somehow that doesnt convince me that all numbers are the same

for any x there exists y such that x = y
for any z there exists y such that z = y

therefore
x = y = z

OMG!!1

>>2
virtual cookie to you.

>>3
ofcourse I say that the proof is wrong. If it'd be correct, we'd be in serious trouble. So it has to be wrong.

Also, I only said that this proved mathematics was useless. But since the proof is wrong, then maths ain't useless.

It's just a thing that looks cool on paper, until you remember the sqare root thingie.

>>6
Indeed, this one is pretty clever.  The error is pretty well hidden.

>>7

a = b.  where's the brilliance?

math-nerds will know calculus but won't ever know how to make love to a girl.

>>9
So?

mega fail, and dumb fucking trick
but it was also the way we discovered irrationals.

>>11


What?


Just what.

Unless you're talking about the concept of a square root. This trick has nothing to do with the discovery of irrationals

When taking square roots, it must be considered that the resultant may be either positive or negative

If you do that, then you also get the options:

-(a-t/2)=b-t/2
-a+t/2=b-t/2
t/2=a+b-t/2
2(t/2)=a+b
t=a+b

or

a-t/2=-(b-t/2)
a-t/2=-b+t/2
a+b-t/2=t/2
a+b=2(t/2)
a+b=t

Equals original equation.
Q.E. fucking D.

>>8
fail, a != b.

ummm i dont get it

Ur a tool

>>9

Math is better than women

>>9

I know how to make love to an infinite series of girl parts that add up to a girl, is that good enough

>>19
yes, that will suffice;

>>19

Depending on the sets, you may be able to reassemble them into an infinite number of girls (Banach, Tarski).

However, the set's elements would be non-measurable, so there's no way to do it with a knife.

I wants lots and lots of some delectable pot!

Marijuana MUST be legalized.