1.

Consider the expansion `(x^(2)+(1)/(x))^(15)`. What is the sum of the coefficients of the middle terms in the given expansion ?A. C(15, 9)B. C(16, 9)C. C(16, 8)D. None of these

Answer» Correct Answer - C
Given `(x^(2)+(1)/(x))^(15)`
Since, n is odd.
So, it has two middle terms `T_(8) and T_(9)`.
`therefore T_(8)+T_(9)=.^(15)C_(7)+.^(15)C_(8)=.^(16)C_(8)" "(because .^(n)C_(r-1)+.^(n)C_(r)=.^(n+1)C_(r))`


Discussion

No Comment Found