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Question : 153 of 180
Marks:
+1,
-0
Solution:
The middle term in the ecpansion of
(1+x)2n is
(+1)th‌term‌i.e.(n+1)th term.
=xn =| 2n(2n−1)(2n−2)....3.2.1 |
| {n(n−1)(n−2)...3.2.1}2 |
xn =| {(2n(2n−2)(2n−4)...4.2}{(2n−1)(2n−3)...(3.1)} |
| {n(n−1)(n−2)...3.2.1}2 |
xn =| 2n{n(n−1)(n−2)...3.2.1}{(2n−1)(2n−3)...3.1} |
| {n(n−1)(n−2)...3.2.1}2 |
xn =| 2n{(2n−1)(2n−3)...3.1} |
| {n(n−1)(n−2)...3.2.1} |
xn =xn2n
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