MCQ
For all real values of  $x$ , increasing function  $f(x)$  is
  • A
    ${x^{ - 1}}$
  • B
    ${x^2}$
  • ${x^3}$
  • D
    ${x^4}$

Answer

Correct option: C.
${x^3}$
c
(c) Since $f(x) = {x^3} \Rightarrow f'(x) = 3{x^2},$

which is non-negative for all real values of $ x.$

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