The "rate of change of flight" doesn't make sense. If you mean the "rate of change of distance flown" then that is the speed. "Reversing" it means going from speed to distance flown. it has nothing at all to do with area.Now
Integral is opposite of derivative
I need a practical example in which if we reverse the rate of change we get area?
iF plane is flying and if we take rate of change of flight then how to reverse it and get area?
I am not getting it!
Again, finding "area under a graph" or "volume" are specific applications of the anti-derivative. You cannot just assert that every application of an anti-derivative must give an "area". I recommend that you go back and review the basic concepts of differentiation and integration.