The function f (x) = 2x3 – 3x2 – 12x + 4, has

Let f(x)= 2x3 – 3x2 – 12x + 4


Applying the first derivative we get



Applying the sum rule of differentiation, so we get



Applying the derivative,


f' (x)=6x2-6x-12


Putting f’(x)=0,we get critical points as


6x2-6x-12=0


6(x2-x-2)=80


x2-x-2=0


Splitting the middle term we get


x2-2x+x-2=0


x(x-2)+1(x-2)=0


(x-2)(x+1)=0


x-2=0 or x+1=0


x=2 or x=-1


Now we will find the value of f(x) at x=-1, 2


f(x)= 2x3 – 3x2 – 12x + 4


f(-1)= 2(-1)3 – 3(-1)2 – 12(-1) + 4=-2-3+12+4=11


f(2)= 2(2)3 – 3(2)2 – 12(2) + 4 =16-12-24+4=-16


Hence from above we find that x=-1 is point of local maxima and the maximum value of f(x) is 11.


Whereas x=2 is point of local minima and the minimum value of f(x) is -16.


So the correct option is option C.


Hence the given function 2x3 – 3x2 – 12x + 4has one maxima and one minima

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