\(\displaystyle (x-y)^2= x^2-2xy+y^2\)

This means that \(\displaystyle (y-x)^2=x^2-2xy+y^2\) too. In other words:

\(\displaystyle (x-y)^2=(y-x)^2\)

Square root of both, and you get some thing weird:

\(\displaystyle (+-)x-y=(+-)y-x\)

How is this possible? Or if it isn't, why isn't it possible?