www.whyslopes.com
Appetizers and Lessons for Mathematics and Reason 
  calculus and preparation for calculus + math education reform, etc.

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.
Try the
Twiddla Whiteboard
to work online with others.

||Définition d'une variable || Algèbre || Arithmetique || Logique ||La raison basée sur les règles et modelés||
[Site Entrance & Hub]Back ] Area Entrance & Hub ] Next ][Site Exit]


Tutors - All Subjects

AU:  tutorfinder.com.au
CDN :  findatutor.ca 
CDN: .i-tutor.ca
CDN: Montreal Tutors
NZ:   findatutor.co.nz
UK:   tutorhunt.com
USA:   wiziq.com
USA: ziizoo.com

use or become a tutor  at your own risk 


YOU are better than YOU think. Show yourself  how:  

      |      
//  _   _ \\
/\             /\
  <|  (o)   (o)   |> 
 \     | |      / 

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

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

 -/[]\- 
||
   / \_ 
 ||||||||||||||||||||||||||||

 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;

      |      
//  _   _ \\
/\             /\
<|   (o)   (o)  |> 
     | |     |
   \             /   
\    =   /

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

 -/[]\- 
||
  _ / \     
 ||||||||||||||||||||||||||||

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.

Chapter 6
Slopes and Vertical Shifts

The vertical shift or motion of a curve y = f(x) adds a constant d (the displacement) to each point. It yields a new curve y = f(x)+d. The next diagram indicates an example.

A simple vertical shift or motion may change the height of a skier, but not the slope of his or her skis.

Constant Difference Theorem

What can be said for sure about two functions when they have the same slope (or derivative) everywhere? One response is given by the following assertion. [Constant Difference] If the functions f1(x) and f2(x) have the same non-infinite slope (that is, derivative) m = f¢1(x) = f¢2(x) at every x in an interval (a,b) then the difference
f2(x)-f1(x) = d
is constant for a < x < b. That is, there is a constant d such that
f2(x) = f1(x) +d
for every x in the interval (a,b), This number d does not depend on x. The proof of this assertion is given in the appendices.

Note the assertion says that there is a constant d. It does not say how to find it. Here is an analogy: Saying there is a needle in a haystack, does not say how to find it. Note also the word every. If there is a point x1 in the interval (a,b) where the slope is not defined then no conclusions can be drawn from the Constant Difference theorem.

Remark.   If f1(x) and f2(x) satisfy the conditions (hypotheses) in the Constant Difference theorem with f2(c) = A and f2(c) = B at some point c in the interval (a,b) then at x = c,
d = f2(x)-f1(x) = f2(c)-f1(c) = A-B
This says how to compute the value of d.

Remark.   Mathematical assertions and theorems which say that a number (or limit) is not defined or does not exist actually mean that a finite number (or finite limit) does not exist. The vertical motion theorem given above applies only when the common slope is finite in the interval (a,b) of interest.

Different vertical displacements over different portions of the trail are possible. The next diagram gives examples of this. Upshifts have been made in the topmost curve of the previous diagram.

Between a and b, between b and c and between c and d, the two trails y = f1(x) and y = f2(x) shown have the same slope but not the same heights. At the ski jump and cliffs in the upper trail y = f1(x), the slope is not defined.

Where Slopes are Not Defined

On a ski trail y = h(x), there may be a few places where the slope is undefined or a single slope to the graph or trail does not exist. In the following diagram, the slope is undefined at the ski jump above the point x = a. At sharp peaks and kinks, a short ski may pivot or rotate while keeping in contacting with one point, the kink or peak on the trail. So a single slope to the trail cannot be defined there. Where the trail has some vertical jumps, the graph ceases to be the graph of a function. The slope is said to be undefined or not to exist here, even though we might say it is infinite, +¥ or -.

Consider the next diagram. At the points a,b,c,d and e, the slope function or derivative m = h¢(x) cannot be given a single value. In general, a single value cannot be assigned to slopes at sharp changes in the direction of a curve y = h(x).

The study of generalized slopes or gradients replaces the discussion of a single slope to a point on a curve by the discussion the set of slopes to a point on a curve. This set based discussion is too complicated to be examined further here.

 But a single slope may sometimes be defined before and after such kinks or sharp turns in the graph of a function.

The ski at the sharp peak is shown pivoting, that is rotating, as the ski passes over.1 In pivoting at the peak, a ski can have many orientations or slopes without intersecting the curve y = h(x) on either side.

1The slope values during this rotation form a set, the slope set. The value 0 belongs to this set.

Problem for Advanced Students. A graph with vertical segments is not the graph of a function, but it may be the image of a parameterized curve (x(t),y(t)) where t belongs to some interval. Show that if (xj(t),yj(t)) are two continuous curves parameterized by t Î [a,b], then (x1¢(t),y1¢(t)) = (x2¢(t),y2¢(t)) for all t Î (a,b) implies there are constants d1 and d2 such that (xj(t),yj(t)) = (xj(t),yj(t))+(d1,d2).

This problem is both a consequence and an extension, a generalization, of the constant difference theorem just stated. It applies to some graphs with vertical segments.

www.whyslopes.com
Volume 3,  Why Slopes and More Math
-  

Foreword, One Calculus  preview and Online Chapters: (V) signals video (RealPlayer Format)  to watch 

Area Entrance & Hub
Foreword
Chapter Descriptions
1. Introduction
2. Calculus Starter Lesson
2. Second Preview Begins
2 Skier in Motion (V)
2 The Skier (V)
2. Position Dependent (V)
3 Slope & Extrema (V)
4 Single Factor Analysis (V)
4 Two Factor (V)
4 More Factors (V)
4 With Divisors (V)
5 Maxima & Minima Tests
6 Jumps & Discontinuities
8 Review  (optional)
9 On Calculus Studies
11 Slope of Slope
13  Acceleration
14 Limits & Error Control (V)
14 Limit of a Fn.
14. Limited Error Control
14 Signif. Digits
14 Cauchy Limits
14 Sequence Limits
14 Decimal Arith.
15 What is Slope (V)
15 Slope Calculation (V)
15 Slope, a Limit
15 Tangent Lines
15 Linear Approx.,
15 Limits via Algebra (V)
15 Recap.
PS.Chain Rule for Polys
PS Chain Rule- General  (V) -
PS More Chain Rule (V)
PS - Sign Analysis (V)
16 What is Velocity
17  What is Area
18 Integration
18 Area Calculation
18  Fn DefN, 6 Ways
19 Logs & Powers
19 Natural Log.
19 Exponential Fn.
20 What's Next
21 Add Vectors
22 Complex #'s
23 Complex #'s
23 Trig Identity
23 Proofs of.
24 Complex Logs etc

Units in Calculations:
7 Velocity
7 Varying Velocity Example
7. Velocity Calculation
7 Changing Units
7 Same Velocity  Motions
10 Slopes without Units.
10 Units & Slopes
10  Units in Cost vs. Quantity
10  How Units  Appear
10 Unit  Elimination
10 Partial Elimination
10 Interest & Units
12 More on Units
Content Guide

Enriched material: The Appendices of Volume 3 are located in the Real  Analysis  Area.

Pigeon Hole Principle
Constant Difference Thm
Continuous Functions
Rational Functions
Mean Value Theorem
One Side Range Theorem
Range On One Side Theorem
Integration & Lipschitz
 Continuity


These appendices continue the
decimal viewpoint of limits, error
control and continuity begun
in Chapter 14. The One Sided
 Range Theorem
is a postscript,
not in printed version.



Online Volume 2, Three Skills for Algebra, Chapters 1 to 25 - skip 18., verbalizes and explains key skills and concepts, those needed in calculus, again to make the hard easier. A visual understanding of complex numbers may help - serve as back ground info,  in partial fraction decomposition.

 

 


www.whyslopes.com

[Top of this Page] [Site Exit] Back ] Area Entrance & Hub ] Next ]
[Comments, Reactions, Feedback][ Road Safety Message ]
: Favourite SitesBBC News  and mathematics portion of  English National Curriculum  



All trademarks and copyrights on this page are owned by their respective owners.
Copyright to comments & contributions are owned by the Poster. 
The Rest © 1995 onward by site author,   Alan Selby,
a 1983 McGill. Ph. D. in mathematics
All Rights Reserved.