已知x²-x-1=0,则(x⁴+2x+1)/x⁵=
问题描述:
已知x²-x-1=0,则(x⁴+2x+1)/x⁵=
答
x²-x-1=0x²=x+1两边平方得x⁴=(x+1)²=x²+2x+1=(x+1)+2x+1=3x+2x⁵=x⁴*x=(3x+2)x=3x²+2x=3(x+1)+2x=5x+3于是(x⁴+2x+1)/x⁵=[(3x+2)+2x+1]/(5x+3)=(5x+3)/(5x+...