yes I agree with all above.
the equation you give is the stock equation of a working electrical engineer, for the voltage on a cap that's charging from a voltage v via a resistor r.
Heres a sheet of the maths that's generally useful in general hard switched smps work.
Generally theres rarely a need to do integration, unless you are doing research style work.
I had a junior engineer telling me that laplace transforms would be needed to design a 5w boost converter......but not so.
I think its good if people know what integration is but don't worry if you cant remember standard integrals. as you know, Integration is just the act of finding the total of some quantity by splitting it into a large number of equal pieces and then summing those up.......rarely is it used outside of research as theres standard forms etc.