Introducing integral in textbooks

  • #1
Hill
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I was very surprised to read the following in Needham, Visual Complex Analysis:

"It is therefore doubly puzzling that the Trapezoidal formula is taught in every introductory calculus course, while it appears that the midpoint Riemann sum RM is seldom even mentioned."

I was surprised because I clearly remember that in my school (long time ago, in a country far away) the midpoint approximation of a curve was the main visualization for integral while the trapezoidal one has been mentioned but deemed unnecessary.

I wonder if Needham is right and if so, why is it different?
 
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  • #2
We had Darboux, called it Riemann, and no trapezoid - and Lebesgue should have been in my opinion.
 
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  • #3
fresh_42 said:
We had Darboux, called it Riemann, and no trapezoid - and Lebesgue should have been in my opinion.
Why Lebesgue in an introductory calculus course of all places? Fwiw we did Darboux and called it Riemann too (trapezoid was part of a numerical methods course that mostly discussed better methods) but I don't think it helped me much...except in terms of gaining an appreciation for how these things are formalized I guess.
 
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  • #4
haider said:
Why Lebesgue in an introductory calculus course of all places?
Well, firstly for the pun with yet another name. And I regret that I didn't add Archimedes to the row.

Secondly, I am of the opinion that we should start to teach mathematics at school, nowadays more than ever. WA can do all that silly algorithmic stuff we use to torture kids with. It has never been mathematics, it is algorithmics, maybe computing, or calculating, but definitely not mathematics. Darboux or Riemann or the trapezoid rule are all adjustments of Archimedes, 300 B.C. Just as if we hadn't developed mathematics in the meantime. Archimedes can be taught in 1 or 2 hours. It is the application of volumes. Lebesgue requires the understanding of volumes.

haider said:
Fwiw we did Darboux and called it Riemann too (trapezoid was part of a numerical methods course that mostly discussed better methods) but I don't think it helped me much...except in terms of gaining an appreciation for how these things are formalized I guess.
 
  • #5
Does anybody here possess Needham's book? I would like to see the entire quotation plus context plus chapter plus page.

"... the Trapezoidal formula is taught in every introductory calculus course ..." is right away wrong as two out of two answers show. And by the way: every and all are never true in real life. I really dislike such claims. So maybe we do Needham wrong here as we cannot verify the claim. And maybe Needham just used it as a rhetorical means for what he really wanted to say.
 
  • #6
fresh_42 said:
Does anybody here possess Needham's book? I would like to see the entire quotation plus context plus chapter plus page.

"... the Trapezoidal formula is taught in every introductory calculus course ..." is right away wrong as two out of two answers show. And by the way: every and all are never true in real life. I really dislike such claims. So maybe we do Needham wrong here as we cannot verify the claim. And maybe Needham just used it as a rhetorical means for what he really wanted to say.
IMG_0112.jpeg
IMG_0111.jpeg
 
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  • #7
So Needham is indeed to blame for that casual statement. I would have thought that a British would know that the world is a bit bigger than San Fransisco. Disappointing. Particularly disappointing is the fact that he does not distinguish between calculus and numerical mathematics. The methods that are used in a calculus book are completely irrelevant as both are simply ##O(x).##
 
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  • #8
fresh_42 said:
So Needham is indeed to blame for that casual statement.
Yes.
I enjoy reading his book, but he makes such statements from time to time.
How right is the following one?

1699733735524.png
 
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  • #9
What constitutes a "geometric" interpretation, one wonders?
 

FAQ: Introducing integral in textbooks

What is an integral, and why is it important in mathematics?

An integral is a fundamental concept in calculus that represents the area under a curve or the accumulation of quantities. It is important because it allows us to calculate things like areas, volumes, central points, and other concepts that are essential in various fields of science and engineering.

How is the concept of an integral introduced in textbooks?

Textbooks often introduce integrals by first discussing the concept of the area under a curve. They typically start with simple geometric shapes and then move to more complex functions. The formal definition of the definite integral is usually presented using the limit of a Riemann sum, followed by the Fundamental Theorem of Calculus.

What are the different types of integrals covered in introductory textbooks?

Introductory textbooks generally cover two main types of integrals: definite integrals and indefinite integrals. Definite integrals compute the net area under a curve between two points, while indefinite integrals represent a family of functions and include an arbitrary constant.

What are some common methods for solving integrals introduced in textbooks?

Common methods for solving integrals include substitution, integration by parts, partial fraction decomposition, and trigonometric substitution. Textbooks often provide step-by-step examples and exercises to help students practice these techniques.

How do textbooks typically explain the Fundamental Theorem of Calculus?

Textbooks usually explain the Fundamental Theorem of Calculus in two parts. The first part states that if a function is continuous over an interval, then its indefinite integral can be used to find the definite integral. The second part states that the derivative of the indefinite integral of a function is the original function. This theorem links differentiation and integration, showing that they are inverse processes.

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