k = 0-2x & lt; 0x & gt; 0
K is not equal to 0k>;; 0f(2)& lt; 0f(3)& lt; 0
k & lt0-b/2a & lt; 2 f(2)& lt; 0
2 & lt=-b/2a & lt; = 3 f(-b/2a)& lt; 0
-b/2a & gt; 3 f(3)& lt; 0
Simplify the above situation and pay attention to the conditions of the value range.