A) [2, 3]
B) (2, 3)
C) \[(-\infty ,\,2)\]
D) \[(3,\,\infty )\]
Correct Answer: B
Solution :
\[y=f(x)=2{{x}^{3}}-15{{x}^{2}}+36x+1\] \[\frac{dy}{dx}=f'(x)=6{{x}^{2}}-30x+36=6({{x}^{2}}-5x+6)\] \[f'(x)=6(x-2)(x-3)\] To be monotonic decreasing, \[f'(x)<0\] \[\Rightarrow (x-2)(x-3)<0\Rightarrow x\in (2,3)\].You need to login to perform this action.
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