If , where [x] denotes the greatest integer function, then
f(x) is continuous at x=0
maximum value of f(x) is 1 in interval
f(x) is discontinuous at ,
f(x) is differentiable at
Clearly f(x) is discontinuous at
etc.
General value corresponding to
maximum value of f(x) in is 1 at
f(x) is discontinuous and non differentiable at x=0. therefore choice (d) is not correct.
Hence (b) is the correct answer.
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