In case (1) 1 = 0. Then using and from Friday,
|
|
- Rosamond Fleming
- 5 years ago
- Views:
Transcription
1 Math 316, Intro to Analysis The order of the real numbers. The field axioms are not enough to give R, as an extra credit problem will show. Definition 1. An ordered field F is a field together with a nonempty subset P F (called the set of positive elements) such that (1) P is Closed under addition: For all a, b P (2) P is Closed under multiplication: For all a, b P (3) The Trichotomy law: For all x F exactly one of the following holds: (a) (b) (c) Proposition 2 (1 is positive.). Let F be an ordered field and 1 be the multiplicative identity, then 1 P Proof. Suppose for the sake of contradiction that 1 / P. According to the trichotomy law then either (1) 1 = 0 or (2) 1 P. Since P, we let p P. In case (1) 1 = 0. Then using and from Friday, p = 1 p = =, contradicting the trichotomy law because. In case (2) 1 P. Then using from Friday, p = p, Since 1 P we see by closure under multiplication that contradicting the trichotomy law because. The additive and order properties of R can be summarized as: Axiom (2). R is an ordered field. This doesn t look like an ordering does it? involving the symbol <. You might have been expecting something Definition 3. Let F be an ordered field and P be its set of positive elements. If a, b F then we say that a < b if, a > b if a b if, and a b if 1
2 2 Let s begin by proving some properties which inequality should have. Theorem 4 (Properties of <). Let F be an ordered field and a, b, c F. Then (1) (Additivity) If a < b then a + c b + c. (Fill in the blank) (2) (Transitivity) If a < b and b < c then a c. (Fill in the blank) (3) (Multiplicativity) If a < b and 0 < c then a c b c. (Fill in the blank) (4) (Multiplicativity II) If a < b and c < 0 then a c b c. (Fill in the blank) (5) If a 0 then a 2 := a a 0 Together we will prove (1) and (5) Proof. Start by writing down the assumption (at the top) and the conclusion (at the bottom). Then do some magic to get from the start to the end. We ll start with the proof of the first claim: That for all a, b, c F if a < b then a + c b + c. Consider any a, b, c F. Assume that. This means that. Thus,. From this it follows that. This completes the proof of the first result. Now we will prove the fifth claim. Consider any a F. Assume a 0. According to the trichotomy law, since a 0, either (1) or (2). In case (1) by closure under multiplication, it follows that, and we are done. In case (2) by closure under multiplication, it follows that additive inverse it follows that. ( Which property? Name it which means that. By properties of ) Thus, in either case. This completes the proof.
3 Our next goal is a discussion of the action of raising real numbers (or any element of an ordered field) to a natural number. Definition 5. Let F be a field. For any x F and any natural number n N we define x n recursively by x 1 = x and x n = x x n 1 if n > 1. How should order behave under exponentiation? Theorem 6. Let F be an ordered field (1) Let x F and n be a natural number. If x > 1 then 1 x n (2) Let x F and n be natural number. If 0 < x < 1 then 1 x n (3) Let x = 1 and n be a natural number. Then 1 x n In order to prove this we will need to recall the proof technique called mathematical induction. Proof technique. Let P (n) be a statement which makes sense for every natural number n N. (For example P (n) might be n is even. ) If you can prove that (Base Case) P (1) is true and (Inductive step) For all n N P (n) implies P (n + 1) then you have proven that P (n) is true for all n. Let s prove claims (3) and (1) of Theorem 6: Proof of claim 3. Let F be a field and x = 1. Base Case We must show that x Inductive step Consider any n N. Assume that x n 1. We must show that x n+1 1. Thus, by the principle of mathematics induction, If x = 1 then x n+1 1 for all n N. That was the easy step, though. Now let s see how well the proof generalizes to the first claim Proof of claim 1. Let F be an ordered field and x > 1. Base Case We must show that x 1 1.
4 4 Inductive step Consider any n N. Assume that x n 1. We must show that x n+1 1. Thus, by the principle of mathematics induction, If x > 1 then x n+1 1 for all n N. Absolute value. Continuing from last time, let F be an ordered field. The following function should be familiar. Definition 7 (Absolute Value). The absolute value function on the ordered field F, is defined by if x 0 x = if x < 0 Let s begin by proving some basic (and hopefully familiar) properties of the absolute value. Theorem 8. Let F be an ordered field. let a, b F. Then (1) a 0 (2) a a (3) a a a (4) ab a b (5) If b 0 (b 1 ) ( b ) 1 (6) a b if and only if b a b. (7) The Triangle inequality. a + b a + b (8) a b a b The Triangle inequality is by far the most important (and hardest to prove) of these. We ll talk though the proof of (3) and (6) because we ll need them in the proof of the triangle inequality (7). Proof of claim 3. Let F be an ordered field. Let a F. There are two cases: (1) a 0 or (2) a < 0. In case (1) a =, so that the claimed inequality amounts to proving the inequalities and. One of these is a truism since a = a. To see the second notice that since a 0, a a a, completing the proof in case (1). In case (2) a = 0. By the transitivity law, then, so that the claimed inequality amounts to proving the inequalities and. One of these is a truism since
5 a = a. To see the second notice that since a 0, a a a, completing the proof in case (1). 0. By the transitivity law, then Proof of claim 6. Let F be an ordered field and consider any a, b F. ( ) Assume that a b. We must show that b < a and a < b. Since a 0 and b a we have that b 0. Again we will make a case-wise attack. Either (1) a 0 or (2) a < 0. In case 1, a = so that the assumption a b becomes, which proves one of the needed inequalities. By the trichotomy law, a 0. Since b 0, it follows that b 0 a and by transitivity completing the proof in this case. In case 1, a = so that the assumption a b becomes. 5 Multiplying both sides by 1 and using Theorem 4, claim (4) we see. This proves one of the desired inequlities. Since b 0, it follows that b 0 a and by transitivity completing the proof in this case. Thus, if a b then b a b. Suppose now that b a and a b. We must show that a < b. Again we make a case-by-case proof. Either (1) a 0 or (2) a < 0. In the first case a = and the inequality to be proven become which is precisely the (first or second?) of the assumed inequalities. In the second case a = and the inequality to be proven become which is precisely the (first or second?) of the assumed inequalities. Proof of the triangle inequality. Let F be an ordered field and a, b F. We wish to show that a + b a + b. According to claim (6) this is equivalent to proving that or by factoring out the negative sign that Now using claim (3) a a a and b b b. Adding these inequalities together and using the additivity property of Theorem 4 we see that, which we have already seen to be equivalent to the claimed inequality.
In case (1) 1 = 0. Then using and from the previous lecture,
Math 316, Intro to Analysis The order of the real numbers. The field axioms are not enough to give R, as an extra credit problem will show. Definition 1. An ordered field F is a field together with a nonempty
More informationA lower bound for X is an element z F such that
Math 316, Intro to Analysis Completeness. Definition 1 (Upper bounds). Let F be an ordered field. For a subset X F an upper bound for X is an element y F such that A lower bound for X is an element z F
More informationAxioms for the Real Number System
Axioms for the Real Number System Math 361 Fall 2003 Page 1 of 9 The Real Number System The real number system consists of four parts: 1. A set (R). We will call the elements of this set real numbers,
More informationA lower bound for X is an element z F such that
Math 316, Intro to Analysis Completeness. Definition 1 (Upper bounds). Let F be an ordered field. For a subset X F an upper bound for X is an element y F such that A lower bound for X is an element z F
More informationµ (X) := inf l(i k ) where X k=1 I k, I k an open interval Notice that is a map from subsets of R to non-negative number together with infinity
A crash course in Lebesgue measure theory, Math 317, Intro to Analysis II These lecture notes are inspired by the third edition of Royden s Real analysis. The Jordan content is an attempt to extend the
More informationCHAPTER 8: EXPLORING R
CHAPTER 8: EXPLORING R LECTURE NOTES FOR MATH 378 (CSUSM, SPRING 2009). WAYNE AITKEN In the previous chapter we discussed the need for a complete ordered field. The field Q is not complete, so we constructed
More informationProperties of the Integers
Properties of the Integers The set of all integers is the set and the subset of Z given by Z = {, 5, 4, 3, 2, 1, 0, 1, 2, 3, 4, 5, }, N = {0, 1, 2, 3, 4, }, is the set of nonnegative integers (also called
More informationa + b = b + a and a b = b a. (a + b) + c = a + (b + c) and (a b) c = a (b c). a (b + c) = a b + a c and (a + b) c = a c + b c.
Properties of the Integers The set of all integers is the set and the subset of Z given by Z = {, 5, 4, 3, 2, 1, 0, 1, 2, 3, 4, 5, }, N = {0, 1, 2, 3, 4, }, is the set of nonnegative integers (also called
More informationn n P} is a bounded subset Proof. Let A be a nonempty subset of Z, bounded above. Define the set
1 Mathematical Induction We assume that the set Z of integers are well defined, and we are familiar with the addition, subtraction, multiplication, and division. In particular, we assume the following
More informationMath 242: Principles of Analysis Fall 2016 Homework 1 Part B solutions
Math 4: Principles of Analysis Fall 0 Homework Part B solutions. Let x, y, z R. Use the axioms of the real numbers to prove the following. a) If x + y = x + z then y = z. Solution. By Axiom a), there is
More informationWe want to show P (n) is true for all integers
Generalized Induction Proof: Let P (n) be the proposition 1 + 2 + 2 2 + + 2 n = 2 n+1 1. We want to show P (n) is true for all integers n 0. Generalized Induction Example: Use generalized induction to
More informationDivisibility = 16, = 9, = 2, = 5. (Negative!)
Divisibility 1-17-2018 You probably know that division can be defined in terms of multiplication. If m and n are integers, m divides n if n = mk for some integer k. In this section, I ll look at properties
More informationHomework #2 Solutions Due: September 5, for all n N n 3 = n2 (n + 1) 2 4
Do the following exercises from the text: Chapter (Section 3):, 1, 17(a)-(b), 3 Prove that 1 3 + 3 + + n 3 n (n + 1) for all n N Proof The proof is by induction on n For n N, let S(n) be the statement
More informationStructure of R. Chapter Algebraic and Order Properties of R
Chapter Structure of R We will re-assemble calculus by first making assumptions about the real numbers. All subsequent results will be rigorously derived from these assumptions. Most of the assumptions
More informationMath 10850, fall 2017, University of Notre Dame
Math 10850, fall 2017, University of Notre Dame Notes on first exam September 22, 2017 The key facts The first midterm will be on Thursday, September 28, 6.15pm-7.45pm in Hayes-Healy 127. What you need
More informationLecture 6: Finite Fields
CCS Discrete Math I Professor: Padraic Bartlett Lecture 6: Finite Fields Week 6 UCSB 2014 It ain t what they call you, it s what you answer to. W. C. Fields 1 Fields In the next two weeks, we re going
More informationWell-Ordering Principle. Axiom: Every nonempty subset of Z + has a least element. That is, if S Z + and S, then S has a smallest element.
Well-Ordering Principle Axiom: Every nonempty subset of Z + has a least element. That is, if S Z + and S, then S has a smallest element. Well-Ordering Principle Example: Use well-ordering property to prove
More informationComplete Induction and the Well- Ordering Principle
Complete Induction and the Well- Ordering Principle Complete Induction as a Rule of Inference In mathematical proofs, complete induction (PCI) is a rule of inference of the form P (a) P (a + 1) P (b) k
More informationWORKSHEET MATH 215, FALL 15, WHYTE. We begin our course with the natural numbers:
WORKSHEET MATH 215, FALL 15, WHYTE We begin our course with the natural numbers: N = {1, 2, 3,...} which are a subset of the integers: Z = {..., 2, 1, 0, 1, 2, 3,... } We will assume familiarity with their
More informationInduction 1 = 1(1+1) = 2(2+1) = 3(3+1) 2
Induction 0-8-08 Induction is used to prove a sequence of statements P(), P(), P(3),... There may be finitely many statements, but often there are infinitely many. For example, consider the statement ++3+
More informationMath 104: Homework 1 solutions
Math 10: Homework 1 solutions 1. The basis for induction, P 1, is true, since 1 3 = 1. Now consider the induction step, assuming P n is true and examining P n+1. By making use of the result (1 + +... +
More informationLecture 4: Constructing the Integers, Rationals and Reals
Math/CS 20: Intro. to Math Professor: Padraic Bartlett Lecture 4: Constructing the Integers, Rationals and Reals Week 5 UCSB 204 The Integers Normally, using the natural numbers, you can easily define
More informationExercise 2. Prove that [ 1, 1] is the set of all the limit points of ( 1, 1] = {x R : 1 <
Math 316, Intro to Analysis Limits of functions We are experts at taking limits of sequences as the indexing parameter gets close to infinity. What about limits of functions as the independent variable
More informationSolutions for Homework Assignment 2
Solutions for Homework Assignment 2 Problem 1. If a,b R, then a+b a + b. This fact is called the Triangle Inequality. By using the Triangle Inequality, prove that a b a b for all a,b R. Solution. To prove
More informationChapter 5: The Integers
c Dr Oksana Shatalov, Fall 2014 1 Chapter 5: The Integers 5.1: Axioms and Basic Properties Operations on the set of integers, Z: addition and multiplication with the following properties: A1. Addition
More informationMath 414, Fall 2016, Test I
Math 414, Fall 2016, Test I Dr. Holmes September 23, 2016 The test begins at 10:30 am and ends officially at 11:45 am: what will actually happen at 11:45 is that I will give a five minute warning. The
More informationMATH 2400: PRACTICE PROBLEMS FOR EXAM 1
MATH 2400: PRACTICE PROBLEMS FOR EXAM 1 PETE L. CLARK 1) Find all real numbers x such that x 3 = x. Prove your answer! Solution: If x 3 = x, then 0 = x 3 x = x(x + 1)(x 1). Earlier we showed using the
More informationMath 300 Introduction to Mathematical Reasoning Autumn 2017 Axioms for the Real Numbers
Math 300 Introduction to Mathematical Reasoning Autumn 2017 Axioms for the Real Numbers PRIMITIVE TERMS To avoid circularity, we cannot give every term a rigorous mathematical definition; we have to accept
More informationSeunghee Ye Ma 8: Week 2 Oct 6
Week 2 Summary This week, we will learn about sequences and real numbers. We first define what we mean by a sequence and discuss several properties of sequences. Then, we will talk about what it means
More informationPrinciples of Real Analysis I Fall I. The Real Number System
21-355 Principles of Real Analysis I Fall 2004 I. The Real Number System The main goal of this course is to develop the theory of real-valued functions of one real variable in a systematic and rigorous
More informationMath 421, Homework #6 Solutions. (1) Let E R n Show that = (E c ) o, i.e. the complement of the closure is the interior of the complement.
Math 421, Homework #6 Solutions (1) Let E R n Show that (Ē) c = (E c ) o, i.e. the complement of the closure is the interior of the complement. 1 Proof. Before giving the proof we recall characterizations
More informationMATH 51H Section 4. October 16, Recall what it means for a function between metric spaces to be continuous:
MATH 51H Section 4 October 16, 2015 1 Continuity Recall what it means for a function between metric spaces to be continuous: Definition. Let (X, d X ), (Y, d Y ) be metric spaces. A function f : X Y is
More informationmeans is a subset of. So we say A B for sets A and B if x A we have x B holds. BY CONTRAST, a S means that a is a member of S.
1 Notation For those unfamiliar, we have := means equal by definition, N := {0, 1,... } or {1, 2,... } depending on context. (i.e. N is the set or collection of counting numbers.) In addition, means for
More informationScalar multiplication and addition of sequences 9
8 Sequences 1.2.7. Proposition. Every subsequence of a convergent sequence (a n ) n N converges to lim n a n. Proof. If (a nk ) k N is a subsequence of (a n ) n N, then n k k for every k. Hence if ε >
More information1 Take-home exam and final exam study guide
Math 215 - Introduction to Advanced Mathematics Fall 2013 1 Take-home exam and final exam study guide 1.1 Problems The following are some problems, some of which will appear on the final exam. 1.1.1 Number
More informationMath 410 Homework 6 Due Monday, October 26
Math 40 Homework 6 Due Monday, October 26. Let c be any constant and assume that lim s n = s and lim t n = t. Prove that: a) lim c s n = c s We talked about these in class: We want to show that for all
More informationProof by Contradiction
Proof by Contradiction MAT231 Transition to Higher Mathematics Fall 2014 MAT231 (Transition to Higher Math) Proof by Contradiction Fall 2014 1 / 12 Outline 1 Proving Statements with Contradiction 2 Proving
More informationMath 324 Summer 2012 Elementary Number Theory Notes on Mathematical Induction
Math 4 Summer 01 Elementary Number Theory Notes on Mathematical Induction Principle of Mathematical Induction Recall the following axiom for the set of integers. Well-Ordering Axiom for the Integers If
More informationMATH 301 INTRO TO ANALYSIS FALL 2016
MATH 301 INTRO TO ANALYSIS FALL 016 Homework 04 Professional Problem Consider the recursive sequence defined by x 1 = 3 and +1 = 1 4 for n 1. (a) Prove that ( ) converges. (Hint: show that ( ) is decreasing
More informationCalifornia: Algebra 1
Algebra Discovering Algebra An Investigative Approach California: Algebra 1 Grades Eight Through Twelve Mathematics Content Standards 1.0 Students identify and use the arithmetic properties of subsets
More informationThe Real Number System
MATH 337 The Real Number System Sets of Numbers Dr. Neal, WKU A set S is a well-defined collection of objects, with well-defined meaning that there is a specific description from which we can tell precisely
More information0.Axioms for the Integers 1
0.Axioms for the Integers 1 Number theory is the study of the arithmetical properties of the integers. You have been doing arithmetic with integers since you were a young child, but these mathematical
More informationMATH 324 Summer 2011 Elementary Number Theory. Notes on Mathematical Induction. Recall the following axiom for the set of integers.
MATH 4 Summer 011 Elementary Number Theory Notes on Mathematical Induction Principle of Mathematical Induction Recall the following axiom for the set of integers. Well-Ordering Axiom for the Integers If
More informationDefinition 2.1. A metric (or distance function) defined on a non-empty set X is a function d: X X R that satisfies: For all x, y, and z in X :
MATH 337 Metric Spaces Dr. Neal, WKU Let X be a non-empty set. The elements of X shall be called points. We shall define the general means of determining the distance between two points. Throughout we
More informationGroups. s t or s t or even st rather than f(s,t).
Groups Definition. A binary operation on a set S is a function which takes a pair of elements s,t S and produces another element f(s,t) S. That is, a binary operation is a function f : S S S. Binary operations
More informationSupremum and Infimum
Supremum and Infimum UBC M0 Lecture Notes by Philip D. Loewen The Real Number System. Work hard to construct from the axioms a set R with special elements O and I, and a subset P R, and mappings A: R R
More informationMAT115A-21 COMPLETE LECTURE NOTES
MAT115A-21 COMPLETE LECTURE NOTES NATHANIEL GALLUP 1. Introduction Number theory begins as the study of the natural numbers the integers N = {1, 2, 3,...}, Z = { 3, 2, 1, 0, 1, 2, 3,...}, and sometimes
More informationLecture 3. Theorem 1: D 6
Lecture 3 This week we have a longer section on homomorphisms and isomorphisms and start formally working with subgroups even though we have been using them in Chapter 1. First, let s finish what was claimed
More informationIntroduction to Mathematical Programming IE406. Lecture 3. Dr. Ted Ralphs
Introduction to Mathematical Programming IE406 Lecture 3 Dr. Ted Ralphs IE406 Lecture 3 1 Reading for This Lecture Bertsimas 2.1-2.2 IE406 Lecture 3 2 From Last Time Recall the Two Crude Petroleum example.
More informationMATH 220 (all sections) Homework #12 not to be turned in posted Friday, November 24, 2017
MATH 220 (all sections) Homework #12 not to be turned in posted Friday, November 24, 2017 Definition: A set A is finite if there exists a nonnegative integer c such that there exists a bijection from A
More informationMath 4310 Solutions to homework 1 Due 9/1/16
Math 0 Solutions to homework Due 9//6. An element [a] Z/nZ is idempotent if [a] 2 [a]. Find all idempotent elements in Z/0Z and in Z/Z. Solution. First note we clearly have [0] 2 [0] so [0] is idempotent
More informationBasics of Proofs. 1 The Basics. 2 Proof Strategies. 2.1 Understand What s Going On
Basics of Proofs The Putnam is a proof based exam and will expect you to write proofs in your solutions Similarly, Math 96 will also require you to write proofs in your homework solutions If you ve seen
More informationa = qb + r where 0 r < b. Proof. We first prove this result under the additional assumption that b > 0 is a natural number. Let
2. Induction and the division algorithm The main method to prove results about the natural numbers is to use induction. We recall some of the details and at the same time present the material in a different
More informationContradiction MATH Contradiction. Benjamin V.C. Collins, James A. Swenson MATH 2730
MATH 2730 Contradiction Benjamin V.C. Collins James A. Swenson Contrapositive The contrapositive of the statement If A, then B is the statement If not B, then not A. A statement and its contrapositive
More informationDistance in the Plane
Distance in the Plane The absolute value function is defined as { x if x 0; and x = x if x < 0. If the number a is positive or zero, then a = a. If a is negative, then a is the number you d get by erasing
More information(a) We need to prove that is reflexive, symmetric and transitive. 2b + a = 3a + 3b (2a + b) = 3a + 3b 3k = 3(a + b k)
MATH 111 Optional Exam 3 lutions 1. (0 pts) We define a relation on Z as follows: a b if a + b is divisible by 3. (a) (1 pts) Prove that is an equivalence relation. (b) (8 pts) Determine all equivalence
More informationMath 421, Homework #7 Solutions. We can then us the triangle inequality to find for k N that (x k + y k ) (L + M) = (x k L) + (y k M) x k L + y k M
Math 421, Homework #7 Solutions (1) Let {x k } and {y k } be convergent sequences in R n, and assume that lim k x k = L and that lim k y k = M. Prove directly from definition 9.1 (i.e. don t use Theorem
More informationLecture 8: A Crash Course in Linear Algebra
Math/CS 120: Intro. to Math Professor: Padraic Bartlett Lecture 8: A Crash Course in Linear Algebra Week 9 UCSB 2014 Qué sed de saber cuánto! Pablo Neruda, Oda a los Números 1 Linear Algebra In the past
More informationThe following techniques for methods of proofs are discussed in our text: - Vacuous proof - Trivial proof
Ch. 1.6 Introduction to Proofs The following techniques for methods of proofs are discussed in our text - Vacuous proof - Trivial proof - Direct proof - Indirect proof (our book calls this by contraposition)
More information20 Ordinals. Definition A set α is an ordinal iff: (i) α is transitive; and. (ii) α is linearly ordered by. Example 20.2.
20 Definition 20.1. A set α is an ordinal iff: (i) α is transitive; and (ii) α is linearly ordered by. Example 20.2. (a) Each natural number n is an ordinal. (b) ω is an ordinal. (a) ω {ω} is an ordinal.
More informationMATH 102 INTRODUCTION TO MATHEMATICAL ANALYSIS. 1. Some Fundamentals
MATH 02 INTRODUCTION TO MATHEMATICAL ANALYSIS Properties of Real Numbers Some Fundamentals The whole course will be based entirely on the study of sequence of numbers and functions defined on the real
More information2. Introduction to commutative rings (continued)
2. Introduction to commutative rings (continued) 2.1. New examples of commutative rings. Recall that in the first lecture we defined the notions of commutative rings and field and gave some examples of
More informationMathematics 96 (3581) CA 6: Property Identification Mt. San Jacinto College Menifee Valley Campus Spring 2013
Mathematics 96 (358) CA 6: Property Identification Mt. San Jacinto College Menifee Valley Campus Spring 203 Name This class addendum is worth a maximum of five (5) points. It is due no later than the end
More informationBob Brown, CCBC Essex Math 163 College Algebra, Chapter 1 Section 7 COMPLETED 1 Linear, Compound, and Absolute Value Inequalities
Bob Brown, CCBC Essex Math 163 College Algebra, Chapter 1 Section 7 COMPLETED 1 What is the following symbol? < The inequality symbols < > are used to compare two real numbers. The meaning of anyone of
More informationM17 MAT25-21 HOMEWORK 6
M17 MAT25-21 HOMEWORK 6 DUE 10:00AM WEDNESDAY SEPTEMBER 13TH 1. To Hand In Double Series. The exercises in this section will guide you to complete the proof of the following theorem: Theorem 1: Absolute
More informationMathematical Reasoning & Proofs
Mathematical Reasoning & Proofs MAT 1362 Fall 2018 Alistair Savage Department of Mathematics and Statistics University of Ottawa This work is licensed under a Creative Commons Attribution-ShareAlike 4.0
More informationSOME TRANSFINITE INDUCTION DEDUCTIONS
SOME TRANSFINITE INDUCTION DEDUCTIONS SYLVIA DURIAN Abstract. This paper develops the ordinal numbers and transfinite induction, then demonstrates some interesting applications of transfinite induction.
More informationMATH 131A: REAL ANALYSIS
MATH 131A: REAL ANALYSIS NICKOLAS ANDERSEN The textbook for the course is Ross, Elementary Analysis [2], but in these notes I have also borrowed from Tao, Analysis I [3], and Abbott, Understanding Analysis
More informationLecture 2. Econ August 11
Lecture 2 Econ 2001 2015 August 11 Lecture 2 Outline 1 Fields 2 Vector Spaces 3 Real Numbers 4 Sup and Inf, Max and Min 5 Intermediate Value Theorem Announcements: - Friday s exam will be at 3pm, in WWPH
More informationProofs. 29th January 2014
Proofs 29th January 2014 Housekeeping Your solutions to Problem Sheet 2 are due today at the start of class. Please make sure you have your name on them and that you put them in the correct pile! Don t
More informationMath Lecture 3 Notes
Math 1010 - Lecture 3 Notes Dylan Zwick Fall 2009 1 Operations with Real Numbers In our last lecture we covered some basic operations with real numbers like addition, subtraction and multiplication. This
More informationMath From Scratch Lesson 24: The Rational Numbers
Math From Scratch Lesson 24: The Rational Numbers W. Blaine Dowler May 23, 2012 Contents 1 Defining the Rational Numbers 1 1.1 Defining inverses........................... 2 1.2 Alternative Definition
More informationSequences. We know that the functions can be defined on any subsets of R. As the set of positive integers
Sequences We know that the functions can be defined on any subsets of R. As the set of positive integers Z + is a subset of R, we can define a function on it in the following manner. f: Z + R f(n) = a
More information1.2 Functions What is a Function? 1.2. FUNCTIONS 11
1.2. FUNCTIONS 11 1.2 Functions 1.2.1 What is a Function? In this section, we only consider functions of one variable. Loosely speaking, a function is a special relation which exists between two variables.
More informationTutorial on Axiomatic Set Theory. Javier R. Movellan
Tutorial on Axiomatic Set Theory Javier R. Movellan Intuitively we think of sets as collections of elements. The crucial part of this intuitive concept is that we are willing to treat sets as entities
More informationSequences. Chapter 3. n + 1 3n + 2 sin n n. 3. lim (ln(n + 1) ln n) 1. lim. 2. lim. 4. lim (1 + n)1/n. Answers: 1. 1/3; 2. 0; 3. 0; 4. 1.
Chapter 3 Sequences Both the main elements of calculus (differentiation and integration) require the notion of a limit. Sequences will play a central role when we work with limits. Definition 3.. A Sequence
More informationS15 MA 274: Exam 3 Study Questions
S15 MA 274: Exam 3 Study Questions You can find solutions to some of these problems on the next page. These questions only pertain to material covered since Exam 2. The final exam is cumulative, so you
More informationCardinality and ordinal numbers
Cardinality and ordinal numbers The cardinality A of a finite set A is simply the number of elements in it. When it comes to infinite sets, we no longer can speak of the number of elements in such a set.
More informationMath 328 Course Notes
Math 328 Course Notes Ian Robertson March 3, 2006 3 Properties of C[0, 1]: Sup-norm and Completeness In this chapter we are going to examine the vector space of all continuous functions defined on the
More informationLecture 2: Change of Basis
Math 108 Lecture 2: Change of asis Professor: Padraic artlett Week 2 UCS 2014 On Friday of last week, we asked the following question: given the matrix A, 1 0 is there a quick way to calculate large powers
More informationQuiz 1, Mon CS 2050, Intro Discrete Math for Computer Science
Quiz 1, Mon 09-6-11 CS 050, Intro Discrete Math for Computer Science This quiz has 10 pages (including this cover page) and 5 Problems: Problems 1,, 3 and 4 are mandatory ( pages each.) Problem 5 is optional,
More informationPEANO AXIOMS FOR THE NATURAL NUMBERS AND PROOFS BY INDUCTION. The Peano axioms
PEANO AXIOMS FOR THE NATURAL NUMBERS AND PROOFS BY INDUCTION The Peano axioms The following are the axioms for the natural numbers N. You might think of N as the set of integers {0, 1, 2,...}, but it turns
More informationLecture 16 : Definitions, theorems, proofs. MTH299 Transition to Formal Mathematics Michigan State University 1 / 8
Lecture 16 : Definitions, theorems, proofs MTH299 Transition to Formal Mathematics Michigan State University 1 / 8 Meanings Definition : an explanation of the mathematical meaning of a word. Theorem :
More informationMath 118: Advanced Number Theory. Samit Dasgupta and Gary Kirby
Math 8: Advanced Number Theory Samit Dasgupta and Gary Kirby April, 05 Contents Basics of Number Theory. The Fundamental Theorem of Arithmetic......................... The Euclidean Algorithm and Unique
More informationCMSC 27130: Honors Discrete Mathematics
CMSC 27130: Honors Discrete Mathematics Lectures by Alexander Razborov Notes by Geelon So, Isaac Friend, Warren Mo University of Chicago, Fall 2016 Lecture 1 (Monday, September 26) 1 Mathematical Induction.................................
More informationMIDTERM REVIEW FOR MATH The limit
MIDTERM REVIEW FOR MATH 500 SHUANGLIN SHAO. The limit Define lim n a n = A: For any ε > 0, there exists N N such that for any n N, a n A < ε. The key in this definition is to realize that the choice of
More informationOutline. We will now investigate the structure of this important set.
The Reals Outline As we have seen, the set of real numbers, R, has cardinality c. This doesn't tell us very much about the reals, since there are many sets with this cardinality and cardinality doesn't
More informationPeano Axioms. 1. IfS x S y then x y (we say that S is one to one).
Peano Axioms To present a rigorous introduction to the natural numbers would take us too far afield. We will however, give a short introduction to one axiomatic approach that yields a system that is quite
More informationMathematical Induction
Mathematical Induction MAT231 Transition to Higher Mathematics Fall 2014 MAT231 (Transition to Higher Math) Mathematical Induction Fall 2014 1 / 21 Outline 1 Mathematical Induction 2 Strong Mathematical
More informationNOTES (1) FOR MATH 375, FALL 2012
NOTES 1) FOR MATH 375, FALL 2012 1 Vector Spaces 11 Axioms Linear algebra grows out of the problem of solving simultaneous systems of linear equations such as 3x + 2y = 5, 111) x 3y = 9, or 2x + 3y z =
More informationEssential Background for Real Analysis I (MATH 5210)
Background Material 1 Essential Background for Real Analysis I (MATH 5210) Note. These notes contain several definitions, theorems, and examples from Analysis I (MATH 4217/5217) which you must know for
More informationSection 3.1: Definition and Examples (Vector Spaces), Completed
Section 3.1: Definition and Examples (Vector Spaces), Completed 1. Examples Euclidean Vector Spaces: The set of n-length vectors that we denoted by R n is a vector space. For simplicity, let s consider
More informationExercises 1 - Solutions
Exercises 1 - Solutions SAV 2013 1 PL validity For each of the following propositional logic formulae determine whether it is valid or not. If it is valid prove it, otherwise give a counterexample. Note
More informationResearch Methods in Mathematics Homework 4 solutions
Research Methods in Mathematics Homework 4 solutions T. PERUTZ (1) Solution. (a) Since x 2 = 2, we have (p/q) 2 = 2, so p 2 = 2q 2. By definition, an integer is even if it is twice another integer. Since
More informationBasic Proof Examples
Basic Proof Examples Lisa Oberbroeckling Loyola University Maryland Fall 2015 Note. In this document, we use the symbol as the negation symbol. Thus p means not p. There are four basic proof techniques
More informationMath 31 Lesson Plan. Day 5: Intro to Groups. Elizabeth Gillaspy. September 28, 2011
Math 31 Lesson Plan Day 5: Intro to Groups Elizabeth Gillaspy September 28, 2011 Supplies needed: Sign in sheet Goals for students: Students will: Improve the clarity of their proof-writing. Gain confidence
More informationRon Paul Curriculum Mathematics 8 Lesson List
Ron Paul Curriculum Mathematics 8 Lesson List 1 Introduction 2 Algebraic Addition 3 Algebraic Subtraction 4 Algebraic Multiplication 5 Week 1 Review 6 Algebraic Division 7 Powers and Exponents 8 Order
More informationClimbing an Infinite Ladder
Section 5.1 Section Summary Mathematical Induction Examples of Proof by Mathematical Induction Mistaken Proofs by Mathematical Induction Guidelines for Proofs by Mathematical Induction Climbing an Infinite
More information11.1 Vectors in the plane
11.1 Vectors in the plane What is a vector? It is an object having direction and length. Geometric way to represent vectors It is represented by an arrow. The direction of the arrow is the direction of
More informationn(n + 1). 2 . If n = 3, then 1+2+3=6= 3(3+1) . If n = 2, then = 3 = 2(2+1)
Chapter 4 Induction In this chapter, we introduce mathematical induction, which is a proof technique that is useful for proving statements of the form (8n N)P(n), or more generally (8n Z)(n a =) P(n)),
More information