Binomial TheoremHard
Question
If the sum of the co-efficients in the expansion of (1 + 2x)n is 6561, then the greatest term in the expansion for x = 1/2 is :
Options
A.4th
B.5th
C.6th
D.none of these
Solution
3n = 6561 (put x = 1)
⇒ n = 8
⇒ 8 - r + 1 ≥ r ⇒ r ≤
⇒ r = 4 (5th term is greatest)
⇒ n = 8
⇒ 8 - r + 1 ≥ r ⇒ r ≤
⇒ r = 4 (5th term is greatest)Create a free account to view solution
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