KVPY2012MathematicsBinomial Theorem
The coefficient of x²⁰¹² in 1+x (1+x² )(1-x) is -
Options
- A2010
- B2011
- C2012
- DNone of these
Correct answer
D. None of these
Step-by-step solution
Coeff. Of x²⁰¹² (1+x)² (1+x² ) (1-x² ) =(1+x)² (1-x⁴ )⁻¹= (1+2 x+x² ) (1-x⁴ )⁻¹ Coeff. Of x²⁰¹²+2 Coeff of x²⁰¹¹+ Coeff of x²⁰¹⁰ in the expansion of (1-x⁴ )⁻¹x²⁰¹¹ and x²⁰¹⁰ not possible in (1-x⁴ )⁻¹= only coeff. Of x²⁰¹² in the expassion of (1-x⁴ )⁻¹ 1+503-1 503 =1