Appetizers and Lessons for Mathematics and Reason (www.whyslopes.com)
||Définition d'une variable || Algèbre || Arithmetique || Logique ||La raison basée sur les règles et modelés||

Online Volumes
1,  Elements of Reason.
1A. Pattern Based Reason 
1B. Math Curriculum Notes
2. Three Skills for Algebra
3. Why Slopes & More Math

 (Optional Book Orders)
More Site Areas 
1. Help Your Child or Teen Learn 
2. Solving Linear Equations
3. Fractions Ratios Rates Proportions & Units
4. Euclidean Geometry
5. Analytic Geometry/Functions 
6. Number Theory
7. More Calculus
More Site Areas 
8. Complex Numbers 
9. Qc Maths  Education  
10. Secondary IV(?) maths
11. Real  Analysis 
12. LaTeX2HotEqn:
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14.  Français
15. Algebra, Odds & Ends, Etc
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16. Math Education Essays
17. Telling & Working with Time
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19. Quantitative Skills for  home, shopping and work 
20. Statistics Useful, or Not.
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to work online with others.

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YOU are better than YOU think. Show yourself  how:  

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Read  logic chapters 1 to 5  in online volume Three Skills for Algebra  for greater skills & confidence in  work 
and study

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 Logic chapters 1 to 5  re- appear not in sequence, as is or longer,  in  Volume 1A,  Pattern Based Reason, Bon Appetite.

Logic Mastery
 Amazing, Amusing, Amorous,  Delicious, Delightful, Edifying, Strengthening Elixir. 
It eases work & learning difficulties Makes the hard easier. Opens eyes. Leads to greater precision.
in reading and
writing

Logic mastery makes the hard, easier. Logic mastery  leads to better, stronger and richer comprehension.  Logic mastery  improves reading and writing.  Logic mastery ease learning difficulties.  Logic mastery gives a headstart.  In sum, logic mastery  will develops critical thinking, improve reading and writing, and give a firmer base for work and studies at many levels. Good luck.


After logic  (a) continue reading Three Skills for Algebra, chapters 8 to 14  and do so alongside site area on solving liinear Equations ; or (b) see this calculus starter lesson and Volume 3, Why Slopes  & More Math, chapters 2 to 6;

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Caution: Site advice is approximately correct, for some circumstances, not all. That leaves room for thought

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What may be learnt and when depends on how skills and concepts are developed. Making the hard easier and clearer will allow earlier & richer development of skills and concepts.


Try the Twiddla Whiteboard. In principle, it  allows to people to draw and chat together online on a copy of this webpage or a clean sheet. The chat may be via text or audio.  Visit www.twiddla.com to set up whiteboards to work with the webpage of your choice.

For online automated help in senior high school maths & calculus, visit  quickmath.com  For Automatic Calculus and Algebra Help with derivatives, integrals, graphs, linear equations, matrix algebra, visit calc101.com  With  overlap, each site quickmath & calc101offers a different range of services, some free, some not, all based on webmathematica. Good luck.

4. Functions and Relations

Site Objective: Clarify and Provide a context for the set-based description and codification of functions and relations.


The set based notion that a function can be represented or codified by a set of ordered pairs is useful, but the notion that writing y = f(x) indicates that y depends on x should come first. 

Functions and Relations

In modern pure mathematics, functions and the allied concept of relations are identified with sets of ordered pairs. That provides the eventually useful, set-theoretic viewpoint. Yet before it you should meet and understand the previous, broader and impure  dependency viewpoint.


Logical or Pedagogical Preparation (Pre-requisites)

  1. Word have been missing or used unclearly in mathematics.  The introduction of the notion of what is a variable and a quick review of three skills for algebra, the use of notation in mathematics, and the forward and backward use of formulas in chapters 8 to 14 in Volume 2, Three Skills for Algebra, might fill gaps in the comprehension of algebra, and develop the algebraic maturity needed pedagogically if not logically for the current study of functions and relations.

  2. While we may advocate the greater use of calculators,  courses in calculus and senior secondary school courses still require students to master and understand exact arithmetic with fractions without a calculator and the use of prime numbers and factorization, material that appears in earlier courses.  The site area. Solving Linear Equations   introduction of stick diagrams can be reviewed (despite opposition) so that students may visualize and consolidate some fraction skills and concepts. The site area in full provides students and teachers a model, a lower bound, for the solution of linear equations from one equation in one unknown to systems of n equation in n unknowns where n = 2, 3 or 4.  The site area  Solving Linear Equations in covering a simpler topic also develops a greater algebraic maturirty,needed pedagogically if not logically for the current study of functions and relations.


The following two columns point to a thought-based introduction of functions suitable I hope for math 436 in Quebec.

Column I
Functions Before Sets
(Cover First)

Column II
Functions with a
Set-Theoretic Focus

Methods to Define Computation and Assignment Rules :

  1. Using Formulas (with use of function notation to indicate dependence of one number or quantity on several others. (math 436)
  2. Using Arrow Diagrams, Tables and Sets of Ordered Pairs (listed or plotted) - functions with finite domains. (math 436)
  3. Using Curves and Infinite Sets of Points in the Plane - When the vertical rule holds, a set of points or curve in the plane can be used to define a function f(x) via the vertical line method.  Note:  Graphing a function f gives a set of points or curve in the plane for which the vertical line method for computing a function yields the same function f. (math 436)
  4. Functions with Infinite Domains - a few exercises (math 436)

For students who have met slopes and/or polynomials before the discussion of functions, the Geometric and Algebraic previews of calculus will provide motivation for the study of slopes (why slopes) and for the factorization of polynomials.  The algebraic previews will develop more algebraic skills and concepts, and still greater algebraic maturity needed pedagogically if not logically for the current study of functions and relations.  These examples may be woven into the monoticity analysis discussion of on what intervals, real-valued  function y = f(x) of a single real variable x are increasing or decreasing. and what intervals those functions are positive, negative or zero.  A point is given by a very short interval.

Item I on the right hand side provides related mateirial


 


Curve or  Set Viewpoint of Functions and Relations

In the foregoing examples, you have seen sets appear in the description of the domains and ranges of functions, and in the definition of function using sets of ordered pairs. The latter implies or suggest the Set Based View and Codification of what is a function in site pages with the following ideas. (Here are more ideas for math 436).

  1. Set Existence and Construction (technical starting point)
  2. Interval Notation. Next (?) see Domains and ranges for a zoo of functions using interval notation.
  3. Assignment and Computation Rules without & then with ordered pairs.
  4. Concept of a Relation, a Set-Based Codification and Generalization.
  5. Why call a set of ordered pairs a relation? Numerical Exercise Included.
  6. Source, Target, Domain and Range Set for functions and relations - plus Definition of subjection, injections and  bijections - set viewpoint
  7. Injectivity of Real Valued Functions - injectivity, one-to-one, two-to-one, many-to- one, or not one- to-one.
  8. Sign Analysis, Zero Analysis, Where are functions positive, negative or zero?
  9. Monotonicity Analysis: Where are functions increasing, decreasing etc. (Includes Optional: Why strictly increasing and strictly decreasing functions are one to one, that is, injective. )
    .
  10. Extrema or Max-Min Analysis Where do they have their greatest and least values. What are minima and maxima.
  11. Exercises with Formulas and Graphs - Numerical Experience (!)
  12. Domains and ranges for a zoo of functions using interval notation.
  13. The absolute Value Function (Qc math 536)
  14. Functions Revisited (for teachers, if not students)

Lessons Elsewhere:

 The website Purplemath offers the following lessons

Functions & Relations Continued
More Lessons here

  1. (FN) Absolute Value

  2. (FN) Step, Sawtooth & Abs. Value

  3. (FN) Horizontal Line Rule Examples

  4. (FN) Inverse Functions Examples

  5. (FN) More Ways to Define  Examples

The last five Lessons 12 to 15 are for students in secondary V mathematics 536  Those lessons require mastery of the earlier lessons.  The calculus introduction pages

  1.  Function Domains
  2.  Polynomials - Domain & Range

may help as well.

 

www.whyslopes.com
Lesson & Lesson Plans for
Sec IV (Maths 436)


a reference for learning and teaching functions, polynomials, solving linear systems, 
powers + exponents + bases + radicals (roots) , quadratic formulas, equations of straight lines

1A. Master Logic
1B. Problems Solving Method
2A Solve Linear Equations i
2B.Solve Linear Equation II
2C Use Equal Sign Properly
2D. Perfect Arithmetic Skills
3 Words & Symbols
3 Goals to Set for Students
4 Use Equations Backwardly
5. Master Functions & Relations
6. Exponents & Radicals I
6 Exponents & Radicals II
7. Straight Lines
8. Polynomials (x,/,+/-)
9. Quadratics
10 Prove it
13 Similarity Scale Factors
12 Trig & Triangles
14 Statistics
MEQ Intermediate Objectives
Remarks for Teachers


Sit down and study - no one else can do that for you.

Advice and Directions
What to do in School   & Why
How to Study Maths & Why

Preparing for Science 

Good News: If you can learn to follow a multi-step methods in any subject precisely, you should be able to do so in other subjects, as well. Hint: Start with arithmetic

Words Before Symbols: 
What is a Variable?
Level:  Secondary II to VI, or Grades 7 to 12)
Introduction
Variation between Examples

Variation of Letters

A letter denotes a variable

Cases of Double Variation

Three Notions of a Variable

Constants, Parameters
& Variables

Talking about numbers
Dependent or Independent
Variable, a Matter of Choice

Complex number starter lesson  

Arithmetic Videos
Fractions
Primes
Greatest Common Divisors

Least Common Multiples

Square Root Simplification

Arithmetic Videos

Decimal Addition Methods
Decimal Subtraction Methods
Decimal Multiplication Methods
Decimal Division Methods


Fraction Starter Lesson
(simplify, multiply, divide & 
then add or subtract)


 

 

 



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a 1983 McGill. Ph. D. in mathematics
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