Binomial TheoremHard
Question
In the expansion of 
, n ∈ N, if the sum of the coefficients of x5 and x10 is 0, then n is :
, n ∈ N, if the sum of the coefficients of x5 and x10 is 0, then n is :Options
A.25
B.20
C.15
D.None of these
Solution
General term =
(-1)n-r x5r-2n If 5r - 2n = 5, then 5r = 2n + 5 ⇒ r =
+ 1If 5r - 2n = 10, then 5r = 2n + 10 ⇒ r =
+ 2Let n = 5k
Now
⇒
= 0⇒ k = 3 ⇒ n = 15
Create a free account to view solution
View Solution FreeMore Binomial Theorem Questions
The remainder when 599 is divides by 13 is -...If the middle term in the expansion of is 924 x6, then n =...If (1 + x)n = C0 + C1x + C2 x2 + ...+ Cnxn, then the value of 12 C1 + 22 C2 + 32 C3 + ...+ n2 Cn is -...If |x| < 1, then the co-efficient of xn in the expansion of (1 + x + x2 + x3 +....)2 is...In the expansion of -...