Is the Domain of an Antiderivative Always a Subset?

PFuser1232
Messages
479
Reaction score
20
Isn't the domain of the derivative of a function a subset of the domain of the function itself?
Does this mean that the domain of an integrand is always a subset of the corresponding indefinite integral?
 
Physics news on Phys.org
We know that if a function ## g ## has a derivative ## h ##, then ##dom(h)\subseteq dom(g)##.

Let ## f ## be our function and ## F ## be any of its corresponding antiderivatives. Then since ## F ## has a derivative ## f ##, it follows that ##dom(f)\subseteq dom(F)##.
 
The domain of the derivative is always a subset of the domain of the function but not necessarily equal. for example, the function f(x)= |x| has domain "all real numbers" while it derivative, f'(x)= 1 if x> 0, -1 if x< 0, as domain "all real numbers except 0".
 
Back
Top