www.whyslopes.com:  Parents:  Help Your Child/ Teen Learn
Appetizers and Lessons for Mathematics and Reason  (Français)
Online tutor-teacher seminars available

Online Volumes (Book Orders)
1,  Elements of Reason. (1996)
1A. Pattern Based Reason  (1995)
1B. Math Curriculum Notes (1996)
2. Three Skills for Algebra  (1995)
3.-Why Slopes & More Math  - (1995)

Read chapters 1-5, 8-12, 14, 16 & 17 
in  Three Skills for Algebra 

More Site Areas 
1.  Solving Linear Equations  (04-2005)
2.  Fractns, Rates Proportns, Units  (2006)
3.  Algebra, Odds & Ends, HS level-(2001)
4.  Euclidean Geometry  & Cmplx NOs-new 
5.  Analytic Geometry/Functions (2006)
6.  Number Theory. (2006-7)
7.  Complex Numbers (2001)
8.  Calculus Introduction (2005)
More Site Areas 
99   Real  Analysis (1995)
10. Secondary IV(?) maths (2006-7)
11. Math Education Essays  (2006-7)
12. LaTeX2HotEqn: (2004)
13. Electric Circuits Etc  (2007)
14. Quebec Math Ed (2004 -8))
15  Prequel to the How-TOs (06-2008)
16-Virtual-Classroom (Take a peek)
Tutor -Teacher-How TOs-(08- 2008)
1. Arithmetic Reference
2. Algebra 
3. More Algebra 
4. Geometry  
5. More Geometry
6. Calculus
7. Logics in Maths
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YOU are better than YOU think. Show yourself  how:

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 For better work & study skills, read logic chapters 1 to 5  in  Three Skills for Algebra. Sooner is better. Good luck.

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 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

Do not leave here without it -  Logic mastery  will develops critical thinking, improve reading and writing, and give a firmer base for work and studies at many levels. Good luck.

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Caution: Site advice is approximately correct, for some circumstances, not all. Site How-TOs are logically developed, but not tried and tested. That leaves room for thought and refinement..

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After logic  (a) continue reading Three Skills for Algebra, chapters 8 to 14  and do so alongside site area on solving linear2007 Equations ; or (b) see this calculus starter lesson and Volume 3, Why Slopes  & More Math, chapters 2 to 6;


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.


Explore collaborative whiteboards from groupboardtwiddla  or scriblink.


Vacuously True Implications
Chapter 22, part II

Previous: Contrapositive Form of Implication, Chapter 22, part I.

The one-way implication rule If A then B is said to be vacuously true if and only if the situation A never occurs.

The contrapositive If NOT B then NOT A is vacuously true if and only if the situation NOT B never occurs, that is if and only if the situation B always occurs. Therefore an implication rule and its contrapositive are vacuously true in different circumstances.

Finally, an innovation perhaps, the two-way implication rule A if and only if B is said to be vacuously true in the situation where A and B are both always true or both always false.

An implication rule says that when a first situation A occurs then so must a second situation B. The associated contrapositive implication rule says that when the second situation B does not occur, then the situation A cannot occur. The previous part of this chapter explains why an implication rule is never disobeyed if and only if its contrapositive is never disobeyed. In consequence, a chain of reasoning which shows the contrapositive form of an implication rule is never disobeyed also shows the implication rule is never disobeyed.


Next: Chapter 23Truth Table for Implications from Occurrence Tables


www.whyslopes.com
Volume 1A, Pattern Based Reason

 Chapters 1 to 24

FOREWORD
Three Remarks

1 Introduction
2 Communication
3. Elements of Reason
4 Implication Rules
5. Deception
6 Chains of Reason
7 Longer Chains
For & From Consistency
8. Language Change
9 Next Chapters
10 Responsibility
11 Accidental Patterns
12 Knowledge Islands
13 Euclidean Logic
14 Deductive & Empirical 
     Views of Mathematics

15 Objectivity
16 Origin of Rules
and Patterns
17 Objective Ways

18. Waking up
19. Symbols  & Logic
20. Pronouns or Symbols
21. Truth Tables I.
22. Truth Tables II
22. Biconditional
22. Contrapositive
23. IF-THEN table
24. Indirect Reason Again

To reason often means to persuade someone of the need for an idea or action. That someone could be yourself. So be careful.

1A Logic Postscripts
- online only

+Proof by Absurdity alias proof by contradiction
+How the demand for consistency supports the law of the excluded middle
+Reality versus or with the aid of Imagination
+Links for reason, logic and crtical thinking
+Three Remarks
+History Lost or Missing

There is a difference between
knowing how to spend money,
and having money to spend.

There is likewise a difference
between mastering a skill
and having meeting a situation in which it applies.

 



 


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