When x
When-1/2
When x & gt=2, f (x) = 2x+1+x-2 = 3x-1
if-3x+ 1 >； 4, then X.
If x+3 >; 4, then x> 1 and-1/2.
If 3x-1>; 4, then x & gt5/3, x & gt=2, take the intersection: x & gt=2.
The solution set thus obtained is: (negative infinity,-1)U( 1, positive infinity).
Find the minimum value:
When x
When-1/2
When x & gt=2 and F(x)=3x- 1, the minimum value is obtained when x=2 and F(2)=5.
To sum up, the minimum value of F(x) is 5/2.