已知x2-5x+1=0,求x⁴+1/x⁴的值
问题描述:
已知x2-5x+1=0,求x⁴+1/x⁴的值
x2是x的二次方
答
x2-5x+1=0
x^2/x-5x/x+1/x=0
x+1/x=5
x^2+1/x^2
=(x+1/x)^2-2
=5^2-2
=23
x^4+1/x^4
=(x^2+1/x^2)^2-2
=23^2-2
=527