Two middle terms in expansion of {left( {x - frac{1}{x}} right)^{11}} are

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7.Binomial Theorem

easy

Two middle terms in the expansion of ${\left( {x - \frac{1}{x}} \right)^{11}}$ are

A

$231x$ and $ \frac{{231}}{x}$

B

$462x$ and $\frac{{462}}{x}$

C

$ - 462x$ and $\frac{{462}}{x}$

D

None of these

Solution

(c) Middle term of ${\left( {x – \frac{1}{x}} \right)^{11}}$is ${T_6} = {\,^{11}}{C_5}{(x)^6}{\left( { – \frac{1}{x}} \right)^5} = – 462\,x$

and ${T_7} = {\,^{11}}{C_6}{(x)^5}{\left( { – \frac{1}{x}} \right)^6} = \frac{{462}}{x}$

Standard 11

Mathematics

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