Vaillan2018-08-09 12:30:06

孩子问:

x = 1+ x^2

上面两边除x:1 = 1/x +x

两个相加:x+1 = 1 + 1/x +x +x^2

得:0 = 1/x + x^2

得:x^3 = -1, x=-1

代入:x = 1+ x^2, -1=1+(-1)^2=2,

-1=2

恨