ok I wanna clear my broad views upon calculus.. first of all I wuz taught calculus 2-3 years back with differentials and Integration.. and ever since iam not really interested in doing this because I wanna know wot iam doing ? I wanna know how do they occur naturally ? I mean like i know if there is a equation like 3x+4y I wud differentiate subtracting one from the variables and multiplying their power with coefficients.. now iam doing BE Telecommunication, 2nd year, 4 semester, In our semester we have a subject thats related to maths and we do differentiate and integrate in those subjects.. but iam still not able to get the perspective ? like right now we are studying about cylindrical and spherical coordinates, I understood that in cylindrical coordinates fy is the ground distance covered by the point to the rectangular x axis and p and z blah.. I wanna get to the main point that is.. I came across this formula.. thats the formula for surface element and that is S=pdfy dz I hope ur getting the formula ? it was also depicted in the book with the help of a diagram ? but I didnt really get it.. there were these differential areas.. what are those? we got through a problem in which we had to find volume and surface.. we used differntials and integrals using limits.. I just want to know what differentials and integrals are all about ? I mean a practical example ? like whats differentials are integrals in nature? where do they exist? I want an example like if we write apple then yea an apple comes to our mind.. like whats the shape and color.. can I get such an example for differentials and Integrals ? I really wanna make myself clear on these two topics.. because I guess every application uses these two methods... and I never knew why do they always come in the middle.. and I hate it when I dont know anything abt it.. I just dont like adding and subtracting things like a dumb... and yea I may sound like a dumbster.. but can any one plz give me a huge lecture or explaination regarding differentials and integrals ? I would be really glad if so.. plz help me !