(x-1)^2=ax^5+bx^4+cx^3+dx^2+ex+f(x-1)^2=x^2-2x+1所以a=0. b=0,c =0, d=1,e =-2, f=1a+b+c+d+e+f=1-2+1=0b+d=0+1=1
