i was trying to learn programming for differential equations ...

i was able to come up with a simple example for differential equation ...

The (standard) calculus is broken into two pieces.

i) Differential calculus - which is looking at the instantaneous rates of change of objects with respect to some variables. We have the notion of the derivative of a function.

ii) Integral calculus - which is calculating the area under curves, calculating volumes and so on. This is all given in terms if the (indefinite or definite) integral of a function.

The two notions are tied together via the fundamental theorem of calculus. This says that the derivative and indefinite integral are basically mutual inverses (but not quite)

i have a few doubts about declaring f(x) ... theta , d^2y/dx^2 ...An equation containing the derivatives of one or more dependent variables, with respect to one of more independent variables, is said to be a differential equation

then i saw this page on the internet .. i do not have this book ...

could somebody please tell me the right methods to declare

f(x) ... theta , d^2y/dx^2 ...

??