设x的3次方+x的负3次方=2,求x+1*x的值
问题描述：
设x的3次方+x的负3次方=2,求x+1*x的值
答
x^3+x^(-3)=(x+x^(-1))(x^2-x*x^(-1)+x^(-2))=2(x+1/x)[(x+1/x)^2-2-1]=2(x+1/x)^3-3(x+1/x)-2=0[(x+1/x)^3-(x+1/x)]-2[(x+1/x)+1]=0(x+1/x)[(x+1/x)^2-1]-2[(x+1/x)+1]=0(x+1/x)[(x+1/x+1)(x+1/x-1)]-2(x+1/x+1)=0(...