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JEE Main Mathematics Application of Derivatives 2026 JEE Main 2026 (24 January Shift 2)

JEE Main Mathematics Question (2026) — Solution

Question

Consider the following three statements for the function f:(0, ) R defined by f(x)= | _ e x |-|x-1| : (I) f is differentiable at all x>0. (II) f is increasing in (0,1). (III) f is decreasing in (1, ). Then.

Options

  1. A. All (I), (II) and (III) are TRUE.
  2. B. Only (II) and (III) are TRUE.
  3. C. Only (I) is TRUE.
  4. D. Only (I) and (III) are TRUE.

Answer

D. Only (I) and (III) are TRUE.

Step-by-step solution

For 0 For x > 1: f(x) = x - x + 1, f'(x) = 1 x - 1 = 1-x x At x = 1: LHD = 1-1 1 = 0, RHD = 1-1 1 = 0. So f is differentiable at x = 1. (I) TRUE: f is differentiable for all x > 0. (II) FALSE: f is decreasing in (0, 1). (III) TRUE: f is decreasing in (1, ). Only (I) and (III) are TRUE.

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