A) 1
B) 2
C) 3
D) 4
Correct Answer: B
Solution :
Let\[f(x)=x+k{{x}^{-2}}\] \[f'(x)=1-2k{{x}^{-3}}=0\]\[\Rightarrow \]\[x={{(2k)}^{\frac{-1}{3}}}\] \[f''(x)=6k{{x}^{4}}>0\forall x\in (0,\infty )\] \[{{(2k)}^{\frac{1}{3}}}+k{{(2k)}^{\frac{-2}{3}}}>2\]\[k>\frac{32}{27}\] \[\therefore \]least natural number k = 2 Ans.You need to login to perform this action.
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