If x, y are real, show that  is valid only whenÂ
We know that  Â
Now, Â Â Â Â Â Â Â Â
and                Â
The equation  is possible only ifÂ
or if                             (ProvidedÂ
,Â
)
or if      Â
or if           Â
or if                               [∵Â
 is not <0]
or if            x - y = 0
or if                x = y
Hence, the equation  is possible when x = y