If `f(x)=1-x^2-x^3++^(15)+x^(16)-x^(17)` , then the coefficient of `x^2inf(x-1)` is `826` b. `816` c. `822` d. none of these
If `f(x)=1-x^2-x^3++^(15)+x^(16)-x^(17)`
, then the coefficient of `x^2inf(x-1)`
is
`826`
b. `816`
c. `822`
d. none of these
A. 826
B. 816
C. 822
D. none of these
4 views
1 Answers
Correct Answer - B
`f(x) = 1-x+x^(2)-x^(3)+"……"-x^(15)+x^(16)-x^(17)= (1-x^(18))/(1+x)`
`rArr f(x-1)= (1-(x-1)^(18))/(x)`
Therefore, required coefficient of `x^(2)` is equal to coefficient of `x^(3)` in `1-(x-1)^(18)`, which is given by `.^(18)C_(3)=816`.
4 views
Answered