Question
Question: \(2^{n}\)can be expanded by binomial theorem, if....
2ncan be expanded by binomial theorem, if.
A
n.2n−1
B
n.2n+1
C
1C0+3C2+5C4+7C6+....
D
n+12n+1
Answer
1C0+3C2+5C4+7C6+....
Explanation
Solution
The given expression can be written as
(1+x+x2+...)−n=[(1−x)−1]−n=(1−x)nand it is valid only when
=nC0−nC1x+nC2x2+...+(−1)nnCn.xn.