2 x - 2*x - 1
x^2 - 2*x - 1
2 -1 + x - 2*x
-1 + x^2 - 2*x
/ ___\ / ___\ \x + -1 + \/ 2 /*\x + -1 - \/ 2 /
(x - 1 + sqrt(2))*(x - 1 - sqrt(2))
-1.0 + x^2 - 2.0*x
-1 + x*(-2 + x)