InterviewSolution
Saved Bookmarks
| 1. |
Coefficient of x^25 in the expansion of the expression sum_(r = 0)^50 ""^50C_r (2x - 3)^r (2-x)^(n-r)is : |
|
Answer» `""^50C_25` `= ""^50C_0 (2x - 3)^0 . (2-x)^n + ""^50C_1 (2x - 3)^1 (2-x)^(n-1) + ""^50C_2(2x - 3)^2 (2-x)^(n-2) + ……""^50C_50(2x - 3)^n` ` = (x - 1)^50 = ""^50C_0 x^50 - ""^50C_1 x^49 + …….` COEFFICIENT of `x^25` is`-""^50C_25` . |
|