4 3 x - x + 4*x - 16
x^4 - x^3 + 4*x - 16
4 3 -16 + x - x + 4*x
-16 + x^4 - x^3 + 4*x
/ ____\ / ____\ | 1 I*\/ 15 | | 1 I*\/ 15 | (x + 2)*(x - 2)*|x + - - + --------|*|x + - - - --------| \ 2 2 / \ 2 2 /
(((x + 2)*(x - 2))*(x - 1/2 + i*sqrt(15)/2))*(x - 1/2 - i*sqrt(15)/2)
-16.0 + x^4 - x^3 + 4.0*x
/ 2 \ (-2 + x)*(2 + x)*\4 + x - x/
(-2 + x)*(2 + x)*(4 + x^2 - x)
/ 2 \ -16 + x*\4 + x *(-1 + x)/
-16 + x*(4 + x^2*(-1 + x))