Consider the following statements in respect of the function y = [x], x ∈ (-1, 1) where [.] is the greatest integer function: 1. Its derivative is 0 at x = 0.5 2. It is continuous at x = 0 Which of the above statements is/are correct?
Consider the following statements in respect of the function y = [x], x ∈ (-1, 1) where [.] is the greatest integer function: 1. Its derivative is 0 at x = 0.5 2. It is continuous at x = 0 Which of the above statements is/are correct? Correct Answer 1 only
Concept:
Greatest Integer Function: (Floor function)
The function f (x) = is called the greatest integer function and means greatest integer less than or equal to x i.e ≤ x.
The domain of is R and the range is I.
Statement:1 Its derivative is 0 at x = 0.5
We know that the floor function is differentiable at all points except integer points.
Hence, y = is differentiable at x = 0.5
⇒ y = = 0
⇒ dy/dx = 0
Statement:2 It is continuous at x = 0
We know that y = is only continuous in the open interval between integers and discontinuous at all integer values.
∴ Only statement 1 is correct.