Question
Question: If the number of terms in \(\left( x + 1 + \frac{1}{x} \right)^{n}\) (n Î I<sup>+</sup>) is 401 then...
If the number of terms in (x+1+x1)n (n Î I+) is 401 then n is greater than-
A
201
B
200
C
199
D
202
Answer
199
Explanation
Solution
(x+1+x1)n= xn(1+x+x2)n
(1 + x + x2)n is the form a0 + a1x + a2x2 +.....+ a2nx2n
which contains 2n + 1 terms
2n + 1 = 401 ̃ n = 200