@aleksandr-physics

More: https://en.fufaev.org/inhomogeneous-differential-equations-of-first-order

Books by Alexander Fufaev:
1) Equations of Physics: Solve EVERY Physics Problem 
https://en.fufaev.org/physics-equations-book
2) Alexander Fufaev and His Never Ending Story: 
https://en.fufaev.org/lifestory

@empajerek4193

Thank you!
Now I see where it came from.

@limpinggabriel6658

Thank you so much! This explanation makes so much sense.