Fundamentals of calculus
Chapter 2: Integration
Integration is the
converse of differentiation. To understand this better, it must be known that
during differentiation an important information is lost. Let $\frac{dz(x)}{dx}
= z’(x)$. Then, we cannot get back $z(x)$ from $z’(x)$ because, while taking
the difference $z(x+\Delta x) – z(x)$ only the information regarding the
difference between a point in Z axis and a neighbourhood of that point is
retained. But the actual orientation is lost. Throughout this article, unless
stated $\Delta x$ is limited to zero. To see how this could cause the loss of a
piece of information, let me elaborate this with a simple algebraic example. Consider
$a-b = c$ to be true. Then we may write $a – (a-c) = c$, here $b=a-c$.