Q20 of 137 Page 19

#Mark the correct alternative in each of the following

The minimum value of is



Differentiating f(x) with respect to x, we get



Differentiating f’(x) with respect to x, we get



for minima at x=c, f’(c)=0 and f’’(c)>0


f’(x)=0 ⇒ x3=125 or x=5


f’’(5)=7>0


Hence, x=5 is a point of minima for f(x) and f(5)=75 is the minimum value of (x).

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