JEE Main2016MathematicsBinomial TheoremActual
For x ∈ R , x ≠ - 1 , if 1 + x 2016 + x 1 + x 2015 + x 2 1 + x 2014 + … + x 2016 = ∑ i = 0 2016 a i x i , then a 17 is equal to
Options
- A2017 ! 17 ! 2000 !
- B2016 ! 17 !1 999 !
- C2016 ! 16 !
- D2017 ! 2000 !
Correct answer
A. 2017 ! 17 ! 2000 !
Step-by-step solution
S = 1 + x 2016 + x 1 + x 2015 + x 2 1 + x 2014 + … … + x 2015 1 + x + x 2016     . . . i x 1 + x   S = x   1 + x 2015 + x 2 1 + x 2014 + … + x 2016 + x 2017 1 + x     . . . i i i i - i S 1 + x = 1 + x 2016 - x 2017 1 + x ∴ S = 1 + x 2017 - x 2017 Coefficient a 17 = 2017 C 17   = 2017 ! 17 ! 2000 !