A) 0
B) 1
C) 2
D) 3
Correct Answer: A
$ \therefore $ $ \sqrt{n}=(m-2) $ On cubing both sides, we get $ {n^{3/2}}={{(m-2)}^{3}} $ $ {n^{3/2}}=m^{3}-8-3\cdot m\cdot 2,(m-2) $
$ \Rightarrow $ $ {n^{3/2}}=m^{3}-8-6m^{2}+12,m $ Now, $ \frac{1}{2}( \frac{m^{3}-6m^{2}+12m-8}{\sqrt{n}}-n )=\frac{1}{2}( \frac{{n^{3/2}}}{\sqrt{n}}-n ) $ $ =\frac{1}{2}[{n^{3/2-1/2}}-n]=\frac{1}{2}\times 0=0 $