解f(x+1)=x²-4x+1=x²亩者+2x+1-6x=(x+1)²-6(x+1)+6=(x+1)²前知-6(x+1)+6∴f(t)=t²-6t+6∴慧耐消f(x)=x²-6x+6
令t=x+1 则乱段带x=t-1∴f(t)=(t-1)²-4(t-1)+1 =t²燃旦-2t+1-4t+4+1 =t²哗芦-6t+6即f(x)=x²-6x+6
令t=x+1 则x=t-1 然后代换就行了