X^2 (x^2-6x+9) -2^2≤0
(x(x-3))^2 -2^2≤0
(x(x-3)-2)(x(x-3)+2)≤0
(x^2-3x-2=0 ili x^2-3x+2)=0
x=(3+-√17)/2 x=1: x=2
+ - + - +
-----(3-√17)/2---------1----------2----------(3+√1)/2---------------->x
f(-1)>0; f(0)<0;f(1,5)>0; f(3)<0; f(4)>0
x^4-6x^3+9x^2-4≤0 x [(3-√17)/2;1] ∪[2;(3+√17)/2]