LOST TOUCH WITH MATHS

Onam days I have tried some Laplace Transform ( which is commonly used in Network realization and ELECTRICAL circuits ) from mathematics text book. Then I realized the fact that even the basic integration methods like integration by parts and other haven't there in my mind. But the basic for mule in Laplace finished in onam days itself. Parallel y hearing online video classes ..... but it is like a drop of water in the sea....... I dont know where I can reach.