Limit Continuity and Differentiability 7 Question 25

25. For a real number y, let [y] denotes the greatest integer less than or equal to y. Then, the function f(x)=tanπ[(xπ)]1+[x]2 is

(1981,2M)

(a) discontinuous at some x

(b) continuous at all x, but the derivative f(x) does not exist for some x

(c) f(x) exists for all x, but the derivative f(x) does not exist for some x

(d) f(x) exists for all x

Objective Questions II

(One or more than one correct option)

Show Answer

Answer:

Correct Answer: 25. (a,b)

Solution:

  1. Given, f(x)=logx(logx)

f(x)=log(logx)logx

On differentiating both sides, we get

f(x)=(logx)1logx1xlog(logx)1x(logx)2f(e)=1111elog(1)1e(1)2f(e)=1e



NCERT Chapter Video Solution

Dual Pane