Lim n →∞, sqrt(n2-n-1)+nα+β=0 then 8(α+β)

If is equal to

(A) 4
(B) –8
(C) –4
(D) 8

Solution:

Tip for solving this question:

Simplify the limit

Find value of

Step 1 of 3:

Given,

On rationalisation, we get

Step 2 of 3:

In

Here,

Now,

Here,

Step 3 of 3:

Now,

Final Answer:

Hence, Option (C) is correct.