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

 Mathematics Course Designers: LAMP offers food for thought.
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:
13. Electric Circuits Etc  
14.  Français
15. Algebra, Odds & Ends, Etc
More Site Areas 
16. Math Education Essays
17. Telling & Working with Time
18. Maps, Plans & Drawings
19. Quantitative Skills for  home, shopping and work 
20. Statistics Useful, or Not.

Test the
Twiddla Whiteboard


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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.

Read notes and textbooks like a lawyer, so that no nuance, no subtlety and no clause escapes your attention. 

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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.

F.  Source, Target, Domain and Range Set for functions and relations - a lesson in terminology

In defining or describing a function or a relation as a set S of ordered pairs in  product set A x B, we will call A the source set and B the target set.  That being said, the domain of S,

domain(S) = {a in A | there exists at least one b in B with (a,b) in S}

is a proper or improper subset of the target set A. Likewise,  the range of S,

range(S) = {a in A | there exists at least one b in B with (a,b) in S}

 is a proper or improper subset of the target set B. The terminology source and target sets is best understood or visualized in the context of arrow diagrams:

In the above example, the source set = the domain of f while the range set is a subset of the target set {t, a, b, c, d}

Definition of a Surjection

Let f: A --> B be a function.  Then f is a surjection if and only if  range (f) = B. 

The word onto has the same meaning (definition) as surjective.

Definition of an Injection

Let f: A --> B be a function.  Then f is a injection if and only if for all pairs of distinct elements c and d of A, the function values f(c) and f(d) are different.

The word one-to-one, sometimes written as 1:1, has the same meaning (definition) as injective. 

Definition of Bijection

Let f: A --> B be a function. Then f is a bijection if and only if f is an injection and also a surjection.


The next lesson examines the injectivity of real value functions y = f(x) of a real variable x.


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ADVERSTISEMENT

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Analytic Geometry

Area Entrance 
Entrance + Pages Below this page



Pages at Current LevelFNs & Dependency
FN With Finite  Sets
FN Vertical Line Rule
FN Infinite Domains
FN  Sets-Theory
FN Interval Notation
FN: Sets - Continued
(FN) Sets & Relations I
(FN) Relations & Sets
FN Source Target Domain Range
(FN) Injective or Not
(FN) Sign & Zero Analysis
(FN) Increasing/Decreasing
(FN) Extrema
FN Numerical Exercises
FN Step Sawtooth Abs.Value
FN Horizontal Line Rule
FN Inverse Functions
FN Many Ways to Define

Area Entrance
(C) Complex Numbers
(FN) What are Functions?
(FN) Functions - More
SZM: Sign Analysis
(L) Lines Summary
(P) Polynomials (*,+,-)
(Q) Quadratics
(D) Simplify Square Roots
(T) Unit Circle Trig
Conic Sections
Links
More Links
Pages at Above this Page

Extras:  Not all perfect.

Equal Sign Use/Abuse
Real Numbers
Say More Positive
Linear Inequalities
Triangle Inequality
Absolute Value |x|
|x| Eq'ns & Inequalities
Rectangular Coords
Shortest Path
Distance Formulas
Add & Multiply Points
Polar Coordinates
Radians
(A) Vectors
(A) Coordinate Arithmetic
(A) Navigation on Maps
(A) Addition Geometrically
(A) Rotation
(PT) Translations
(PT) Dilatations
PT: Rotations


Links to Site Pages outside this site area follow - co- and pre- requisites.

Road Safety Message

Easy Consequences of  this (newest) Complex Number. Starter Lesson follow below to provide an alternate development of HS or college maths.

Vec & Cmplx  No Applet
B2 C. Conjugates
B3 Pythagoras
B4 Distance
B5 Rt Triangle Similarity
B6 Trig., Functions
B7 Dot & Cross Products
B8 Cosine Law
B9 Exponential & cis fns
B10 Easy Trig Identities
B11 Set Viewpoint

Arithmetic Videos - Real Player Format

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


Fractions
Primes
Greatest Common Divisor
Divisors

Least Common Multiples

Square Root
Simplification

Using formulas forwards & Backwards - A unifying theme for algebra skill development - the 4th skill in Volume 2, Three Skills for Algebra!

What is a Variable?




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The Rest © 1995 onward by site author,   Alan Selby,
a 1983 McGill. Ph. D. in mathematics
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