4 x - 4*x
x^4 - 4*x
/ 3\ x*\-4 + x /
x*(-4 + x^3)
/ 2/3 2/3 ___\ / 2/3 2/3 ___\ / 2/3\ | 2 I*2 *\/ 3 | | 2 I*2 *\/ 3 | x*\x - 2 /*|x + ---- + ------------|*|x + ---- - ------------| \ 2 2 / \ 2 2 /
((x*(x - 2^(2/3)))*(x + 2^(2/3)/2 + i*2^(2/3)*sqrt(3)/2))*(x + 2^(2/3)/2 - i*2^(2/3)*sqrt(3)/2)
x^4 - 4.0*x