已知x²-3x+1=0(x≠0),求值:(1)x²+1/x² (2)x²/(x^4)+x³+1
问题描述:
已知x²-3x+1=0(x≠0),求值:(1)x²+1/x² (2)x²/(x^4)+x³+1
答
由x²-3x+1=0(x≠0),
得x+1/x=3
(1)x²+1/x² =(x+1/x)²-2=3²-2=7
(2)x²/(x^4)+x³+1=1/x²+x³+1=7+1=8