=a√a2−b2−√a2−b2+a√a2−b2.a−√a2−b2b=...........−a2−a2+b2b=.............−b=$\frac{a-b\sqrt{a^{2}-b^{2}} }{\sqrt{a^{2}-b^{2}} }$
=a√a2−b2−√a2−b2+a√a2−b2.a−√a2−b2b=$...........- \frac{a^{2}-a^{2}+b^{2}}{b
\sqrt{a^{2}-b^{2}} }
=.............-b
=\frac{a-b
}{\sqrt{a^{2}-b^{2}} }
=\frac{\sqrt{a-b}
}{\sqrt{a+b} }$