Highly selective Backlog Qs for JEE MainMathematicsLimits
If ( _ x 0 [(a-n) n x- x] n x x^2 =0,(n 0) ) then the minimum possible positive value of (a ) is
Options
- A0
- B-2
- C2
- D1
Correct answer
C. 2
Step-by-step solution
( aligned & _ x 0 ((a-n) n x- x) n x x^2 =0, n 0 & _ x 0 ( (a-n) n x x - x x ) (n x) x =0 & [ _ x 0 n x n x =n ] & n (a n-n^2-1 )=0 a=n+ 1 n , n 0 & n+ 1 n 2 n 1 n (by AM GM) & a 2 1 & a 2 aligned ) ( ) Minimum possible positive value of (a ) is 2. Hence, option (c) is correct.