KVPY2011MathematicsSets and Relations
The sum of (1²-1+1 )(1 !)+ (2²-2+1 )(2 !)+ .+ (n²-n+1 )(n !) is -
Options
- A(n+2) !
- B(n-1)((n+1) !)+1
- C(n+2) !-1
- Dn((n+1) !)-1
Correct answer
B. (n-1)((n+1) !)+1
Step-by-step solution
T _ n = ( n ²- n +1 ) n ! = ( n ²-1 ) n !-( n -2) n ! T _ n =( n -1)( n +1) !-( n -2) n ! Sum =1+( n -1)( n +1) !