比如 (i+1)^n+(1-i)^n=[√2cos(π/4)+?*sin(π/4)]^n+[√2(cos(-π/4)+?*sin(-π/4)]^n=[2^(n/2)]*[cos(πn/4)+?*sin(πn/4)]+[2^(n/2)]*[(cos(-πn/4)+?*sin(-πn/4)]={2^[(n+1)/2)]}*cos(πn/4).