On-line Math 21

On-line Math 21

What is calculus?

As has probably been pointed out to you before, calculus is different, different from any math that you would have seen before calculus. Why? There are two fundamental things that make it different, and those are the things that make it important for you to learn about. The first is that the whole point of calculus is measurement of things, things like slope, area, speed, which we deal with all the time. Until calculus there hadn't been a way to describe accurately, mathematically, those measurements except in very special (simple) cases. Making the measurement of such quantities precise, mathematically, is the fundamental idea of calculus. The other is the idea of modeling, of turning a real situation into a mathematical structure. The mathematical approach to understanding any situation is to strip away all the special circumstances of the situation, so that it looks much like a number of other situations. Then, solving that one general problem solves all the similar situations. We are going to be worried about a lot of modeling situations that could not be dealt with without calculus - that is, without the measurements that calculus makes precise.

Calculus is also a watershed course in your education. It marks the end of courses where finding an ``answer'' is the whole point of a problem. Often in this course, what is important is showing how or why a certain fact is true. It is often frustrating that the fact you have to prove is self-evident. It is also the end of courses where the point is merely manipulation of expressions (that is high-school algebra), or rote memorization. It is the first course in applied mathematics, and the first course in much of pure mathematics. In later mathematics courses the objects studied are often abstract, defined in that Alice-in-Wonderland simplicity that permeates mathematics: a word means exactly what we say it means, no more and no less. But in calculus the point is to measure concepts that we already have definitions for (length of a curve, area, slope). In abstract mathematics courses, the whole universe we consider is defined from the ground up, and we can ascribe to it whatever rules and laws we think are interesting. Not so with calculus. In calculus, we have to deal with the rules as they are.

Here are some more details about the course structure, the differences between a high-school course (even a high-school calculus course) and a college course, how this course will be run, and other administrative details. Course Particulars.

The topics listed here provide various insights into what calculus is, and how we will be dealing with it in this course.

0.1  The area problem

This section explains how the idea of integration, one of the two major tools of calculus, grew out of Greek mathematics.

0.2  Tangent and Velocity Problems

This section introduces the idea of the derivative of a function, in terms of slopes of curves and changes of position with respect to time.

0.3  Achilles and the Tortoise

Another Greek insight into mathematics, this time, infinite sequences and series.

0.4  Sequences and series

A bit more introduction to sequences and series. This idea is mentioned here to give you an insight into the process of limits. You will study it seriously in second-semester calculus.

0.5  Functions

A brief review of the main subject of study, functions. Everything in calculus is expressed in terms of functions. While we presume that you have seen functions before, this will refresh your memory a bit and introduce some of our notation. These are called elementary functions, not because they are so simple, but because they are the basic building-blocks for all functions.

0.6  Modeling

Modeling is the practical ``point'' of calculus. You express a given physical situation abstractly, and the features of it which are just particulars are removed, leaving only the relationships between the components. Those relationships are the same for many different situations, and if we understand how one works, we understand them all. Modeling is the process of moving from a particular situation to its general relationships, which we then will solve mathematically.

By David L. Johnson, last modified 4/4/00.


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On 4 Apr 2000, 22:00.