1  Introduction
In Class XI and in Chapter 5 of the present book, we
discussed how to differentiate a given function f with respect
to an independent variable, i e , how to find f ′(x) for a given
function f at each x in its domain of definition Further, in
the chapter on Integral Calculus, we discussed  how to find
a function f whose derivative is the function g, which may
also be formulated as follows:
For a given function g, find a function f such that
dy
dx  = g(x), where y = f(x)