In the expansion of `(1+x)^n ,` 7th and 8th terms are equal. Find the value of `(7//x+6)^2` .
In the expansion of `(1+x)^n ,` 7th and 8th terms are equal. Find the value of `(7//x+6)^2` .
5 views
1 Answers
Correct Answer - `n^(2)`
Since the `7^(th)` and `8^(th)` terms are equal , we have
`.^(n)C_(6)x^(6) =.^(n)C_(7)x^(7)`
or `x=(.^(n)C_(6))/(.^(n)C_(7))=(7)/(n-6)`
or `(7/x+6)=n^(2)`
5 views
Answered