Question

已知x²-3x+1=0,则x+x负一次方= ,x²+x负二次方= ,x四次方+x负四次方=

Answer 1

1.

x^2-3x+1=0

x^2+1=3x

x+ 1/x=3

①x+1/x^2=(x=1/x)^2-2=7

②x^4+1/x^4=(x^2+1/x^2)-2=47