Question

计算√(2005×2006×2007×2008+1)

Answer 1

设2005=n

原式=根号n(n+1)(n+2)(n+3)+1

=根号(n^2+3n)(n^2+3n+2)+1

=根号(n^2+3n)^2+2(n^2+3n)+1

=根号(n^2+3n+1)^2

=n^2+3n+1