Question

find the middle term (s) in the expansion of (×- 1/ x) 2n​

Answer 1

Answer:

1.3.5...(2n−1)

​  

2  

n

x  

n

Step-by-step explanation:

Middle term in the expansion of (1+x)  

2n

; is =t  

n+1

​  

 

=  

2n

C  

n

​  

.1  

2n−n

.x  

n

 

=  

(2n−n)!n!

(2n)!

​  

.x  

n

 

=  

(n!)(n!)

2n

(2n−1)(  

2n−2

​  

)(2n−3)....  

4

×3×  

2

×1

​  

.x  

n

 

=  

(n!)(n!)

2  

n

[n(n−1)(n−2)....×2×1][(2n−1)(2n−3)....3×1]

​  

x  

n

 

=  

n!

(2n−1)(2n−3)....3×1

​  

2  

n

x  

n