99 Percentile Qs Bank for JEE MainMathematicsLimits
lim x → 1 1 - cos 2 x - 1 x - 1
Options
- Aexists and it equal to 2
- Bexists and it equals - 2
- Cdoes not exist because x - 1 → 0
- Ddoes not exist because the left hand limit is not equal to the right hand limit
Correct answer
D. does not exist because the left hand limit is not equal to the right hand limit
Step-by-step solution
lim x → 1 1 - cos 2 x - 1 x - 1 = lim x → 1 2 sin x - 1 x - 1 But lim x → 1 + 2 sin x - 1 x - 1 = 2 lim x → 1 + sin x - 1 x - 1 = 2 and lim x → 1 – 2 sin x - 1 x - 1 = - 2 lim x → 1 - sin x - 1 x - 1 = - 2 .