Answer:
Surface area =
m².
And domain will be x∈ (0,∞)
Step-by-step explanation:
An open rectangular box with volume 4 m³ has a square base.
The length of a side of the base is x
We can say that 
=> 

Surface area can be found as: 

Surface area =
m².
And domain will be x∈ (0,∞) we can also say x>0
x is greater than zero as the surface area will always be a positive value and x cannot be negative.