｛【（x√y）-（y√x）】/【（x√y）+（y√x）】｝-｛【（y√x）+（x√y）】/【（y√x）-（x√y）】｝=[(x√y-y√x)²+(x√y+y√x)²]/[(x√y-y√x)(x√y-y√x)]=(x²y-2xy√xy+y²x+x²y+2xy√...