Dear rahul

 X=(2+(2-(2+X)^1/2)^1/2)^1/2 

x≥ 0  ................1

^square

x² =(2+(2-(2+X)^1/2)^1/2)

or

x² -2 =(2-(2+X)^1/2)^1/2

so x² -2≥0

   so   x≥2   or x ≤-2

 from equation 1        x≥2

and RHS      2-(2+X)^1/2 ≥ 0

   or     x≤2

 so only x=2 is possible

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