the absolute value of numerically greatest term in the expansion of (1+x)^15, if x= -1/7 is
A) 15/7
B) 15
C) 30/7
D) 195/98
Answer with method, if you don't know then gtfo. Don't spam.
Answers
Answered by
5
Given : expansion of (1+x)^15, if x= -1/7
To Find : absolute value of numerically greatest term in the expansion
Solution:
(1 + x)¹⁵
a +1 th term
ⁿCₐ(1)ⁿ⁻ᵃ(x)ᵃ
n = 15
(1)ⁿ⁻ᵃ = 1 for each a
= ¹⁵Cₐ(-1/7)ᵃ
a = 0
=> ¹⁵C₀(-1/7)⁰ = 1
a = 1 => - 15/7
a = 2 => 105/49 = 15/7
a = 3 => -455/343 < 2
a = 4 => 1365/7⁴ < 1
and terms keep decreasing
15/7 is the largest term
Hence 15/7 is the correct answer
Learn More:
The first three terms in the binomial expansion of ( ) n x y + are 1, 56 ...
brainly.in/question/13197893
evaluate (2+√3)^7 + (2 - √3)^7 by binomial theorem
brainly.in/question/5256736
Use binomial theorem to expand (2+X)5 in ascending powers of x ...
brainly.in/question/11212431
Similar questions