Consider the following statements : I. f(x) is an increasing function. II. f(x) has local maximum at x = 0. Which of the statements given above is/are correct?

Consider the following for the two (02) items that follow : Let the function f(x)=x^{2}+9.

  1. A. I only
  2. B. II only
  3. C. Both I and II
  4. D. Neither I nor II

Correct Answer: D. Neither I nor II

Explanation

For f(x) = x^2+9, the derivative is f'(x) = 2x. The function decreases for x \lt 0 and increases for x \gt 0, so it is not strictly increasing everywhere (I is false). At x=0, f''(0) = 2 \gt 0, which means x=0 is a point of local minimum, not a maximum (II is false).

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