Question

若X+1/X=-1 则1+X+X2+X3+...+X2003=?

Answer 1

x+1+1/x=0

两边乘x

x^2+x+1=0

则三个1组

=(1+x+x^2)+x^3(1+x+x^2)+x^6(1+x+x^2)+……+x^2001(1+x+x^2)

=0+0+0+……+0

=0