已知x+1/x=2,x^2+1/x^2=3,求x^3+1/x^3的值

问题描述:

已知x+1/x=2,x^2+1/x^2=3,求x^3+1/x^3的值

x^3+1/x^3
=(x+1/x)(x^2-1+1/x^2)
=2×(3-1)
=4.