AP EAMCET2004MathematicsBinomial Theorem
Coefficient of x¹⁰ in the expansion of (2+3 x) e^ -x is
Options
- A-26 (10) !
- B-28 (10) !
- C-30 (10) !
- D-32 (10) !
Correct answer
B. -28 (10) !
Step-by-step solution
aligned (2+3 x) e^ -x & & =(2+3 x) (1- x 1 ! + x^2 2 ! - x^3 3 ! + ) aligned Coefficient of x¹⁰ in the above series aligned & = 2 10 ! - 3 9 ! & = 1 10 ! (2-30)= -28 10 ! aligned