Question

((x-y)^2 + 4xy) / (x + y)^2 - 4xy))^1/2

Answer 1

$\sqrt{ \frac{(x-y)^2+4xy}{(x+y)^2-4xy} } = \sqrt{ \frac{x^2 - 2xy +y^2+4xy}{x^2 + 2xy +y^2-4xy} } = \sqrt{ \frac{x^2+2xy+y^2}{x^2-2xy+y^2} } = \sqrt{ \frac{(x+y)^2}{(x-y)^2} } = \frac{x+y}{x-y}$