NTA Abhyas JEE Main2020MathematicsLimitsPractice
If lim x → 0 ( ( a - n ) nx - tan x)sin nx x 2 = 0 , where n is a non zero real number, then a is equal to
Options
- A0
- Bn + 1 n
- Cn
- Dn + 1 n
Correct answer
D. n + 1 n
Step-by-step solution
lim x → 0 ( ( a - n ) n x - tan x)sin  nx x 2 = 0 ⇒     lim x → 0 a - n n - tan  x x sin  nx x = 0 ⇒     a - n n - 1 n = 0 ⇒     a - n n - 1 = 0 ∵  n ≠ 0 ∴       a = n + 1 n