JEE Advanced2017MathematicsLimitsActual
Let f x = 1 - x ( 1 + 1 - x ) | 1 - x | cos ⁡ 1 1 - x for x ≠ 1 , then
Options
- Alim x → 1 + f ( x ) does not exist
- Blim x → 1 - f ( x ) does not exist
- Clim x → 1 - f x = 0
- Dlim x → 1 + f x = 0
Correct answer
A. lim x → 1 + f ( x ) does not exist
Step-by-step solution
f x = 1 - x cos 1 1 - x , x < 1 - 1 + x cos 1 1 - x , x > 1 lim x → 1 + f x = does not exist ; (as cos t can take any value between -1 and 1, so oscillating.) lim x → 1 - f x = 0 : (As cos t term varies between -1 and 1 for any value of t and is multiplied with zero)