For which one of the following functions is the second derivative test inconclusive at ?

MATHEMATICS · Single correct · CBSE · Mathematics · Applications of Derivatives · Applications of Derivatives

Problem

For which one of the following functions is the second derivative test inconclusive at

x=0

? (a)

f(x)=x^{2}

(b)

f(x)=\cos x

(c)

f(x)=x^{3}

(d)

f(x)=\sin x