2 5*x - 4
5*x^2 - 4
/ ___\ / ___\ | 2*\/ 5 | | 2*\/ 5 | |x + -------|*|x - -------| \ 5 / \ 5 /
(x + 2*sqrt(5)/5)*(x - 2*sqrt(5)/5)
-4.0 + 5.0*x^2