Pure Maths – or Pure Fiction?

Ok, after reading Winston Fong over at eatyourmaths  it brought back memories of my old maths teacher.  He wasn’t just a teacher, he was a mathematical genius and would often have us completely bewildered!!

There was one gem that he did produce and it took us forever to get our heads around it at the time.

So, for all you mathematical stars, here is what he presented us with:

Can you prove that 2 = 1?

Assume that x = y

It follows that x – y = 0

And that 2x – 2y = 0

Therfore, x – y = 2x – 2y.

Now, another way of writing 2x – 2y, as any mathematician will agree, is 2(x – y)

And another way of writing x – y is 1(x – y)

So…1(x – y) = 2(x – y)

Divide each side of the equation by (x – y) and you are left with…..1 = 2

Now you can go and scratch your heads as I did many years ago.