The function is defined by

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

Problem

The function

f:\mathbb{R}\to\mathbb{R}

is defined by

f(x)=x^{3}+k x

. Determine the set of all real numbers

k

for which

f

is one-one on

\mathbb{R}

. (a)

k>0

(b)

k<0

(c)

k\ge 0

(d) All real

k