Explanation:
As we can see the question given
f(x) is varying accordingly to the interval
f(x) = 2 if 2<x≤4
The value of function is 2 for the interval 2 to 4
and interval is open at x=2 and closed at x = 4
f(x) = x + 3 if 4<x<8
The value of function is x + 3 and it is open at x = 4 and x = 8
f(x) = 2x if x
8
The value of function is 2x for x greater than or equal to 8
The image is attached for more clearing of doubt