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MHT CET202620 April 2026Morning ShiftMathematicsContinuity and DifferentiabilityActual

Let [x] denotes the greatest integer less than or equal to x and f(x) = [ ^2 x] , then which of the following is true ?

Options

  1. A_ x 0 f(x) does not exist
  2. Bf(x) is continuous at x = 0
  3. Cf(x) is not differentiable at x = 0
  4. Df'(0) = 1

Correct answer

B. f(x) is continuous at x = 0

Step-by-step solution

For x (- /4, /4) , we have -1 Squaring both sides, we get 0 ^2 x Therefore, f(x) = [ ^2 x] = 0 for all x (- /4, /4) . Since f(x) = 0 in a neighborhood of x = 0 , we have _ x 0 f(x) = 0 and f(0) = 0 . Thus, f(x) is continuous at x = 0 . Furthermore, since f(x) is constant in this neighborhood, f'(0) = 0 , meaning f(x) is differentiable at x = 0 . Answer: f(x) is continuous at x = 0

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