Practicing Success

Target Exam

CUET

Subject

-- Mathematics - Section B1

Chapter

Applications of Derivatives

Question:
The function \(f(x)=2x^{3}-3x^{2}-12x+4\) has
Options:
Two points of local maximum
Two points of local minimum
One maxima and one minima
no maxima or minima
Correct Answer:
One maxima and one minima
Explanation:
\(\begin{aligned}f^{\prime}(x)&=0\\ 6x^{2}-6x-12&=0\\ x&=-1,2\\ f^{\prime \prime}(x)&=12x-6\\ f^{\prime \prime}(-1)&=-18<0\\ f^{\prime \prime}(2)&=18>0\end{aligned}\)