4 2 y - 9*y - 10
y^4 - 9*y^2 - 10
/ ____\ / ____\ \x + \/ 10 /*\x - \/ 10 /*(x + I)*(x - I)
(((x + sqrt(10))*(x - sqrt(10)))*(x + i))*(x - i)
4 2 -10 + y - 9*y
-10 + y^4 - 9*y^2
2 / 2\ -10 + y *\-9 + y /
-10 + y^2*(-9 + y^2)
-10.0 + y^4 - 9.0*y^2
/ 2\ / 2\ \1 + y /*\-10 + y /
(1 + y^2)*(-10 + y^2)