显然w不为0,及1
w+1/w+1=0
两边同时乘以w:w^2+w+1=0
两边同时乘以w-1:w^3-1=0
故有w^3=1
w^2008=w^(2007+1)=w
w^(-2008)=1/w
w^2008+w^-2008=w+1/w=-1