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
- A_ x 0 f(x) does not exist
- Bf(x) is continuous at x = 0
- Cf(x) is not differentiable at x = 0
- 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