1.

The sum of (1^(2)-1+1) (1!)+(2^(2)-2+1)(2!) +...+ (n^(2)-n+1) (n!) is -

Answer»

`(N+2)!`
`(n-1)((n+1)!)+1`
`(n+2)!-1`
`n((n+1)!)-1`

SOLUTION :`T_(n)=(n^(2)-n+1)n!`
`=(n^(2)-1)n!-(n-2)n!`
`T_(n)=(n-1)(n+1)!-(n-1)n!`
SUM `=1+(n-1) (n+1) !`


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