Let f x = 1 - x ( 1 + 1 - x ) | 1 - x | cos ⁡ 1 1 - x   for   x ≠ 1 , then

Let fx=1-x(1+1-x)|1-x|cos11-x for x1, then
  1. limx1+f(x) does not exist
  2. limx1-f(x) does not exist
  3. limx1-fx=0
  4. limx1+fx=0

Solution

fx= 1-xcos11-x,x<1-1+xcos11-x,x>1

limx1+fx=does not exist; (as cost can take any value between -1 and 1, so oscillating.)

 

 limx1-fx=0: (As cost term varies between -1 and 1 for any value of t and is multiplied with zero)

Asked in: JEE Advanced 2017 (Paper 2)

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