Saturday, November 11, 2017

Two equals one?


The following is a mathematical proof that two equals one. What's wrong with it? Click below for the answer.
$a = b$
$aa = ab$
$aa - bb = ab - bb$
$(a + b)(a - b) = b(a - b)$
$a + b = b$
$a + a = a$
$2a = a$
$2 = 1$


1 comment:

Trevel said...

CLEARLY the problem is that your opening statement b=a is unproven, but thankfully I've got that for you.

a^2-2ab+b^2 = b^2-2ba+a^2
(a-b)^2 = (b-a)^2
(a-b) = (b-a)
2a = 2b
a = b

Now since I've just proven that, given any two numbers, they are equal, it necessarily follows that 1=2.