4 2 y - 3*y - 4
y^4 - 3*y^2 - 4
4 2 -4 + y - 3*y
-4 + y^4 - 3*y^2
(x + 2)*(x - 2)*(x + I)*(x - I)
(((x + 2)*(x - 2))*(x + i))*(x - i)
-4.0 + y^4 - 3.0*y^2
/ 2\ \1 + y /*(-2 + y)*(2 + y)
(1 + y^2)*(-2 + y)*(2 + y)
2 / 2\ -4 + y *\-3 + y /
-4 + y^2*(-3 + y^2)