Discrete Mathematics: Solutions to Homework (12%) For each of the following sets, determine whether {2} is an element of that set.

Save this PDF as:
 WORD  PNG  TXT  JPG

Size: px
Start display at page:

Download "Discrete Mathematics: Solutions to Homework (12%) For each of the following sets, determine whether {2} is an element of that set."

Transcription

1 Discrete Mathematics: Solutions to Homework 2 1. (12%) For each of the following sets, determine whether {2} is an element of that set. (a) {x R x is an integer greater than 1} (b) {x R x is the square of an integer} (c) {2,{2}} (d) {{2},{{2}}} (e) {{2},{2,{2}}} (f) {{{2}}} (a) Since the set contains only integers and {2} is a set, not an integer, {2} is not an element. (b) Since the set contains only integers and {2} is a set, not an integer, {2} is not an element. (c) The set has two elements. One of them is patently {2}. (d) The set has two elements. One of them is patently {2}. (e) The set has two elements. One of them is patently {2}. (f) The set has only one element, {{{2}}}; Since this is not the same as {2} (the former is a set containing a set, whereas the latter is a set containing a nubmer), {2} is not an element of {{{2}}}. 2. (8%) What is the cardinality of each of these sets? (a) ϕ (b) {ϕ} (c) {ϕ, {ϕ}} (d) {ϕ, {ϕ}, {ϕ, {ϕ}}}

2 (a) The empty set has no elements, so its cardinality is 0. (b) This set has one element (the empty set), so its cardinality is 1. (c) This set has two elements, so its cardinality is 2. (d) This set has three elements, so its cardinality is (12%) Determine whether each of these sets is the power set of a set, where a and b are distinct elements. (a) ϕ (b) {ϕ, {a}} (c) {ϕ, {a}, {ϕ, a}} (d) {ϕ, {a}, {b}, {a, b}} (a) The power set of every set includes at least the empty set, so the power set cannot be empty. Thus ϕ is not the power set of any set. (b) This is the power set of {a}. (c) This set has three elements. Since 3 is not a power of 2, this set cannot be the power set of any set. (d) This is the power set of {a, b}. 4. (5%) Find the sets A and B if A B = {1, 5, 7, 8}, B A = {2, 10}, and A B = {3, 6, 9}. Since A = (A B) (A B), we conclude that A = {1, 5, 7, 8} {3, 6, 9} = {1, 3, 5, 6, 7, 8, 9}. Similarly B = (B A) (A B) = {2, 10} {3, 6, 9} = {2, 3, 6, 9, 10}. 5. (6%) Let A, B, and C be sets. Show that (A B) C = (A C) (B C). First suppose x is in the left-hand side. Then x must be in A but in neither B nor C. Thus x A C, but x / B C, so x is in the right-hand side. Next suppose that x is in the right-hand side. Thus x must be in A C and not in B C. The

3 first of these implies that x A and x / C. But now it must also be the case that x / B, since otherwise we would have x B C. Thus we have shown that x is in A but in neither B nor C, which implies that x is in the left-hand side. 6. (9%) Draw the Venn diagrams for each of these combinations of the sets A, B, and C. (a) A (B C) (b) A B C (c) (A B) (A C) (B C) (a) (b) (c) 7. (3%) Determine whether f is a function from Z to R if (a) f(n) = ±n

4 (b) f(n) = n (c) f(n) = 1/(n 2 4) (Please describe the reason.) (a) This is not a function because the rule is not well-defined. We do not know whether f(3) = 3 or f(3) = 3. For a function, it cannot be both at the same time. (b) This is a function. For all integers n, n is a well-defined real number. (c) This is not a function with domain Z, since for n = 2 (and also for n = 2) the value of f(n) is not defined by the given rule. In other words, f(2) and f( 2) are not specified since division by 0 makes no sense. 8. (4%) Determine whether each of these functions from Z to Z is one-to-one. Please describe the reason. (a) f(n) = n 1 (b) f(n) = n (c) f(n) = n 3 (d) f(n) = n/2 (a) This is one-to-one, since if n 1 1 = n 2 1, then n 1 = n 2. (b) This is not one-to-one, since, for example, f(3) = f( 3) = 10. (c) This is one-to-one, since if n 3 1 = n 3 2, then n 1 = n 2 (take the cube root of each side). (d) This is not one-to-one, since, for example, f(3) = f(4) = (10%) Determine whether f : Z Z Z is onto if (a) f(m, n) = 2m n

5 (b) f(m, n) = m 2 n 2 (c) f(m, n) = m + n + 1 (d) f(m, n) = m n (e) f(m, n) = m 2 4 (Please describe the reason.) (a) This is clearly onto, since f(0, n) = n for every integer n. (b) This is not onto, since, for example, 2 is not in the range. To see this, if m 2 n 2 = (m n)(m + 2) = 2, then m and n must have the same parity (both even or both odd). In either case, both m n and m + n are then even, so this expression is divisible by 4 and hence cannot equal 2. (c) This is onto, since f(0, n 1) = n for every integer n. (d) This is onto. To achieve negative values we set m = 0, and to achieve nonnegative values we set n = 0. (e) This is not onto, for the same reason as in part (b). 10. (8%) Determine whether each of these functions is a bijection from R to R. (a) f(x) = 3x + 4 (b) f(x) = 3x (c) f(x) = (x + 1)/(x + 2) (d) f(x) = x (a) This is a bijection since the inverse function is f 1 (x) = (4 x)/3. (b) This is not one-to-one since f(17) = f( 17), for instance. It is also not onto, since the range is the interval (, 7]. For example, is not in the range.

6 (c) This function is a bijection, but not from R to R. To see that the domain and range are not R, note that x = 2 is not in the domain, and f(x) = 1 is not in the range. On the other hand, f is a bijection from R { 2} to R {1}, since its inverse is f 1 (x) = (1 2x)/(x 1) (d) It is clear that this continuous function is increasing throughout its entire domain (R) and it takes on both arbitrarily large values and arbitrarily small (large negative) ones. So it is a bijection. Its inverse is clearly f 1 (x) = 5 x (4%) Find f g and g f, where f(x) = x and g(x) = x + 2, are functions from R to R. We have (f g)(x) = f(g(x)) = f(x + 2) = (x + 2) = x 2 + 4x + 5, whereas (g f)(x) = g(f(x)) = g(x 2 + 1) = x = x Note that they are not eual. 12. (8%) For each of these lists of integers, provide a simple formula or rule that generates the terms of an integer sequence that begins with the given list. Assuming that your formula or rule is correct, determine the next three terms of the sequence. (a) 3, 6, 11, 18, 27, 38, 51, 66, 83, 102,... (b) 1, 10, 11, 100, 101, 110, 111, 1000, 1001, 1010, 1011,... (c) 0, 2, 8, 26, 80, 242, 728, 2186, 6560, 19682,... (d) 1, 0, 0, 1, 1, 1, 0, 0, 0, 0, 1, 1, 1, 1, 1,... (a) The n-th term is n The next three terms are 123, 146, 171. (b) The n-th term is the binary expansion of n. The next three terms are 1100, 1101, (c) The n-th term is 3 n 1, the next three terms are 59048, , (d) The sequence consists of one 1, followed by two 0s, then three 1s, four 0s, five 1s, and so on, alternating between 0s and 1s and having one more item in each group than in the previous group. Thus six 0 s will follow next, so the next three terms aer 0,0,0.

7 13. (4%) Compute each of these double sums. (a) (b) (c) (d) 3 2 (i j) i=1 j=1 3 2 (3i + 2j) i=0 j=0 3 2 j i=1 j=0 2 3 i 2 j 3 i=0 j=0 (a) 3 (b) 78 (c) 9 (d) (7%) Show that the polynomial function Z + Z + Z + with f(m, n) = (m + n 2)(m + n 1)/2 + m is one-to-one and onto. f(1, 1) = 1 f(2, 1) = 3 f(3, 1) = 6 f(4, 1) = 10 f(5, 1) = 15 f(6, 1) = 21 f(1, 2) = 2 f(2, 2) = 5 f(3, 2) = 9 f(4, 2) = 14 f(5, 2) = 20 f(6, 2) = 27 f(1, 3) = 4 f(2, 3) = 8 f(3, 3) = 13 f(4, 3) = 19 f(5, 3) = 26 f(1, 4) = 7 f(2, 4) = 12 f(3, 4) = 18 f(4, 4) = 25 f(1, 5) = 11 f(2, 5) = 17 f(3, 5) = 24 f(1, 6) = 16 f(2, 6) = 23 f(1, 7) = 22 We see by looking at the diagonals of this table that the function takes on successive values as m + n increases. When m + n = 2, f(m, n) = 1. When m + n = 3, f(m, n) takes on the values 2 and 3. When m + n = 4, f(m, n) takes on the values

8 4, 5, and 6. And so on. It is clear from the formula that the range of values the function takes on for a fixed value of m + n, say m + n = x, is (x 2)(x 1) through (x 2)(x 1) 2 + (x 1), since m can assume the values 1,2,3,..., (x 1) under these conditions, and the first term in the formula is a fixed positive integer when m + n is fixed. To show that this function is one-to-one and onto, we merely need to show that the range of values for x + 1 picks up precisely where the range of values for x left off, i.e., that f(x 1, 1) + 1 = f(1, x). We compute: f(x 1, 1)+1 = (x 2)(x 1) 2 + (x 1) +1 = x2 x = (x 1)x 2 +1 = f(1, x)

9 Extra Exercises: 1. Determine whether these statements are true or false. (a) ϕ {ϕ} (b) ϕ {ϕ, {ϕ}} (c) {ϕ} {ϕ} (d) {ϕ} {{ϕ}} (e) {ϕ} {ϕ, {ϕ}} (f) {{ϕ}} {ϕ, {ϕ}} (g) {{ϕ}} {{ϕ}, {ϕ}} (a) true. (b) true. (c) false- see part (a). (d) true. (e) true- the one element in the set on the left is an element of the set on the right, and the sets are not equal. (f) true- similar to part (e). (g) false- the two sets are equal. 2. Let A = {a, b, c}, B = {x, y}, C = {0, 1}. Find (a) A B C (b) C B A (c) C A B (d) B B B

10 (a) {(a, x, 0), (a, x, 1), (a, y, 0), (a, y, 1), (b, x, 0), (b, x, 1), (b, y, 0), (b, y, 1), (c, x, 0), (c, x, 1), (c, y, 0), (c, y, 1)} (b) {(0, x, a), (0, x, b), (0, x, c), (0, y, a), (0, y, b), (0, y, c), (1, x, a), (1, x, b), (1, x, c), (1, y, a), (1, y, b), (1, y, c)} (c) {(0, a, x), (0, a, y), (0, b, x), (0, b, y), (0, c, x), (0, c, y), (1, a, x), (1, a, y), (1, b, x), (1, b, y), (1, c, x), (1, c, y)} (d) {(x, x, x), (x, x, y), (x, y, x), (x, y, y), (y, x, x), (y, x, y), (y, y, x), (y, y, y)} 3. Prove the first De Morgan law by showing that if A and B are sets, A B = A B. A B = {x x / A B} = {x (x (A B))} = {x (x A x B)} = {x (x A) (x B)} = {x x / A x / B} = {x x A x B} = {x x A B} = A B 4. Show that the set Z + Z + is countable. Problem 14 gave us a one-to-one correspondence between Z + Z + and Z +. Since Z + is countable, so is Z + Z +.

1 The Concept of a Mapping

1 The Concept of a Mapping Arkansas Tech University MATH 4033: Elementary Modern Algebra Dr. Marcel B. Finan 1 The Concept of a Mapping The concept of a mapping (aka function) is important throughout mathematics. We have been dealing

More information

Math 55: Discrete Mathematics

Math 55: Discrete Mathematics Math 55: Discrete Mathematics UC Berkeley, Spring 2012 Homework # 9, due Wednesday, April 11 8.1.5 How many ways are there to pay a bill of 17 pesos using a currency with coins of values of 1 peso, 2 pesos,

More information

Sample Induction Proofs

Sample Induction Proofs Math 3 Worksheet: Induction Proofs III, Sample Proofs A.J. Hildebrand Sample Induction Proofs Below are model solutions to some of the practice problems on the induction worksheets. The solutions given

More information

5.1 Radical Notation and Rational Exponents

5.1 Radical Notation and Rational Exponents Section 5.1 Radical Notation and Rational Exponents 1 5.1 Radical Notation and Rational Exponents We now review how exponents can be used to describe not only powers (such as 5 2 and 2 3 ), but also roots

More information

Solutions for Practice problems on proofs

Solutions for Practice problems on proofs Solutions for Practice problems on proofs Definition: (even) An integer n Z is even if and only if n = 2m for some number m Z. Definition: (odd) An integer n Z is odd if and only if n = 2m + 1 for some

More information

INTRODUCTORY SET THEORY

INTRODUCTORY SET THEORY M.Sc. program in mathematics INTRODUCTORY SET THEORY Katalin Károlyi Department of Applied Analysis, Eötvös Loránd University H-1088 Budapest, Múzeum krt. 6-8. CONTENTS 1. SETS Set, equal sets, subset,

More information

k, then n = p2α 1 1 pα k

k, then n = p2α 1 1 pα k Powers of Integers An integer n is a perfect square if n = m for some integer m. Taking into account the prime factorization, if m = p α 1 1 pα k k, then n = pα 1 1 p α k k. That is, n is a perfect square

More information

3.1. RATIONAL EXPRESSIONS

3.1. RATIONAL EXPRESSIONS 3.1. RATIONAL EXPRESSIONS RATIONAL NUMBERS In previous courses you have learned how to operate (do addition, subtraction, multiplication, and division) on rational numbers (fractions). Rational numbers

More information

Section 2.7 One-to-One Functions and Their Inverses

Section 2.7 One-to-One Functions and Their Inverses Section. One-to-One Functions and Their Inverses One-to-One Functions HORIZONTAL LINE TEST: A function is one-to-one if and only if no horizontal line intersects its graph more than once. EXAMPLES: 1.

More information

3. Mathematical Induction

3. Mathematical Induction 3. MATHEMATICAL INDUCTION 83 3. Mathematical Induction 3.1. First Principle of Mathematical Induction. Let P (n) be a predicate with domain of discourse (over) the natural numbers N = {0, 1,,...}. If (1)

More information

Discrete Mathematics: Homework 7 solution. Due: 2011.6.03

Discrete Mathematics: Homework 7 solution. Due: 2011.6.03 EE 2060 Discrete Mathematics spring 2011 Discrete Mathematics: Homework 7 solution Due: 2011.6.03 1. Let a n = 2 n + 5 3 n for n = 0, 1, 2,... (a) (2%) Find a 0, a 1, a 2, a 3 and a 4. (b) (2%) Show that

More information

Linear Algebra I. Ronald van Luijk, 2012

Linear Algebra I. Ronald van Luijk, 2012 Linear Algebra I Ronald van Luijk, 2012 With many parts from Linear Algebra I by Michael Stoll, 2007 Contents 1. Vector spaces 3 1.1. Examples 3 1.2. Fields 4 1.3. The field of complex numbers. 6 1.4.

More information

Mathematics Review for MS Finance Students

Mathematics Review for MS Finance Students Mathematics Review for MS Finance Students Anthony M. Marino Department of Finance and Business Economics Marshall School of Business Lecture 1: Introductory Material Sets The Real Number System Functions,

More information

Mathematics for Computer Science/Software Engineering. Notes for the course MSM1F3 Dr. R. A. Wilson

Mathematics for Computer Science/Software Engineering. Notes for the course MSM1F3 Dr. R. A. Wilson Mathematics for Computer Science/Software Engineering Notes for the course MSM1F3 Dr. R. A. Wilson October 1996 Chapter 1 Logic Lecture no. 1. We introduce the concept of a proposition, which is a statement

More information

Test1. Due Friday, March 13, 2015.

Test1. Due Friday, March 13, 2015. 1 Abstract Algebra Professor M. Zuker Test1. Due Friday, March 13, 2015. 1. Euclidean algorithm and related. (a) Suppose that a and b are two positive integers and that gcd(a, b) = d. Find all solutions

More information

FINAL EXAM SECTIONS AND OBJECTIVES FOR COLLEGE ALGEBRA

FINAL EXAM SECTIONS AND OBJECTIVES FOR COLLEGE ALGEBRA FINAL EXAM SECTIONS AND OBJECTIVES FOR COLLEGE ALGEBRA 1.1 Solve linear equations and equations that lead to linear equations. a) Solve the equation: 1 (x + 5) 4 = 1 (2x 1) 2 3 b) Solve the equation: 3x

More information

List the elements of the given set that are natural numbers, integers, rational numbers, and irrational numbers. (Enter your answers as commaseparated

List the elements of the given set that are natural numbers, integers, rational numbers, and irrational numbers. (Enter your answers as commaseparated MATH 142 Review #1 (4717995) Question 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 Description This is the review for Exam #1. Please work as many problems as possible

More information

Mathematical Induction. Lecture 10-11

Mathematical Induction. Lecture 10-11 Mathematical Induction Lecture 10-11 Menu Mathematical Induction Strong Induction Recursive Definitions Structural Induction Climbing an Infinite Ladder Suppose we have an infinite ladder: 1. We can reach

More information

Cubes and Cube Roots

Cubes and Cube Roots CUBES AND CUBE ROOTS 109 Cubes and Cube Roots CHAPTER 7 7.1 Introduction This is a story about one of India s great mathematical geniuses, S. Ramanujan. Once another famous mathematician Prof. G.H. Hardy

More information

Domain of a Composition

Domain of a Composition Domain of a Composition Definition Given the function f and g, the composition of f with g is a function defined as (f g)() f(g()). The domain of f g is the set of all real numbers in the domain of g such

More information

Integer roots of quadratic and cubic polynomials with integer coefficients

Integer roots of quadratic and cubic polynomials with integer coefficients Integer roots of quadratic and cubic polynomials with integer coefficients Konstantine Zelator Mathematics, Computer Science and Statistics 212 Ben Franklin Hall Bloomsburg University 400 East Second Street

More information

3.2. Solving quadratic equations. Introduction. Prerequisites. Learning Outcomes. Learning Style

3.2. Solving quadratic equations. Introduction. Prerequisites. Learning Outcomes. Learning Style Solving quadratic equations 3.2 Introduction A quadratic equation is one which can be written in the form ax 2 + bx + c = 0 where a, b and c are numbers and x is the unknown whose value(s) we wish to find.

More information

P. Jeyanthi and N. Angel Benseera

P. Jeyanthi and N. Angel Benseera Opuscula Math. 34, no. 1 (014), 115 1 http://dx.doi.org/10.7494/opmath.014.34.1.115 Opuscula Mathematica A TOTALLY MAGIC CORDIAL LABELING OF ONE-POINT UNION OF n COPIES OF A GRAPH P. Jeyanthi and N. Angel

More information

MA651 Topology. Lecture 6. Separation Axioms.

MA651 Topology. Lecture 6. Separation Axioms. MA651 Topology. Lecture 6. Separation Axioms. This text is based on the following books: Fundamental concepts of topology by Peter O Neil Elements of Mathematics: General Topology by Nicolas Bourbaki Counterexamples

More information

Mathematical Induction

Mathematical Induction Mathematical Induction (Handout March 8, 01) The Principle of Mathematical Induction provides a means to prove infinitely many statements all at once The principle is logical rather than strictly mathematical,

More information

MATHEMATICAL INDUCTION. Mathematical Induction. This is a powerful method to prove properties of positive integers.

MATHEMATICAL INDUCTION. Mathematical Induction. This is a powerful method to prove properties of positive integers. MATHEMATICAL INDUCTION MIGUEL A LERMA (Last updated: February 8, 003) Mathematical Induction This is a powerful method to prove properties of positive integers Principle of Mathematical Induction Let P

More information

This chapter is all about cardinality of sets. At first this looks like a

This chapter is all about cardinality of sets. At first this looks like a CHAPTER Cardinality of Sets This chapter is all about cardinality of sets At first this looks like a very simple concept To find the cardinality of a set, just count its elements If A = { a, b, c, d },

More information

Basic Concepts of Point Set Topology Notes for OU course Math 4853 Spring 2011

Basic Concepts of Point Set Topology Notes for OU course Math 4853 Spring 2011 Basic Concepts of Point Set Topology Notes for OU course Math 4853 Spring 2011 A. Miller 1. Introduction. The definitions of metric space and topological space were developed in the early 1900 s, largely

More information

You know from calculus that functions play a fundamental role in mathematics.

You know from calculus that functions play a fundamental role in mathematics. CHPTER 12 Functions You know from calculus that functions play a fundamental role in mathematics. You likely view a function as a kind of formula that describes a relationship between two (or more) quantities.

More information

Chapter 4 Lecture Notes

Chapter 4 Lecture Notes Chapter 4 Lecture Notes Random Variables October 27, 2015 1 Section 4.1 Random Variables A random variable is typically a real-valued function defined on the sample space of some experiment. For instance,

More information

Math 181 Handout 16. Rich Schwartz. March 9, 2010

Math 181 Handout 16. Rich Schwartz. March 9, 2010 Math 8 Handout 6 Rich Schwartz March 9, 200 The purpose of this handout is to describe continued fractions and their connection to hyperbolic geometry. The Gauss Map Given any x (0, ) we define γ(x) =

More information

Logo Symmetry Learning Task. Unit 5

Logo Symmetry Learning Task. Unit 5 Logo Symmetry Learning Task Unit 5 Course Mathematics I: Algebra, Geometry, Statistics Overview The Logo Symmetry Learning Task explores graph symmetry and odd and even functions. Students are asked to

More information

Note on some explicit formulae for twin prime counting function

Note on some explicit formulae for twin prime counting function Notes on Number Theory and Discrete Mathematics Vol. 9, 03, No., 43 48 Note on some explicit formulae for twin prime counting function Mladen Vassilev-Missana 5 V. Hugo Str., 4 Sofia, Bulgaria e-mail:

More information

Zero: If P is a polynomial and if c is a number such that P (c) = 0 then c is a zero of P.

Zero: If P is a polynomial and if c is a number such that P (c) = 0 then c is a zero of P. MATH 11011 FINDING REAL ZEROS KSU OF A POLYNOMIAL Definitions: Polynomial: is a function of the form P (x) = a n x n + a n 1 x n 1 + + a x + a 1 x + a 0. The numbers a n, a n 1,..., a 1, a 0 are called

More information

Factoring Special Polynomials

Factoring Special Polynomials 6.6 Factoring Special Polynomials 6.6 OBJECTIVES 1. Factor the difference of two squares 2. Factor the sum or difference of two cubes In this section, we will look at several special polynomials. These

More information

To define function and introduce operations on the set of functions. To investigate which of the field properties hold in the set of functions

To define function and introduce operations on the set of functions. To investigate which of the field properties hold in the set of functions Chapter 7 Functions This unit defines and investigates functions as algebraic objects. First, we define functions and discuss various means of representing them. Then we introduce operations on functions

More information

SOLUTIONS TO EXERCISES FOR. MATHEMATICS 205A Part 3. Spaces with special properties

SOLUTIONS TO EXERCISES FOR. MATHEMATICS 205A Part 3. Spaces with special properties SOLUTIONS TO EXERCISES FOR MATHEMATICS 205A Part 3 Fall 2008 III. Spaces with special properties III.1 : Compact spaces I Problems from Munkres, 26, pp. 170 172 3. Show that a finite union of compact subspaces

More information

PUTNAM TRAINING POLYNOMIALS. Exercises 1. Find a polynomial with integral coefficients whose zeros include 2 + 5.

PUTNAM TRAINING POLYNOMIALS. Exercises 1. Find a polynomial with integral coefficients whose zeros include 2 + 5. PUTNAM TRAINING POLYNOMIALS (Last updated: November 17, 2015) Remark. This is a list of exercises on polynomials. Miguel A. Lerma Exercises 1. Find a polynomial with integral coefficients whose zeros include

More information

Representation of functions as power series

Representation of functions as power series Representation of functions as power series Dr. Philippe B. Laval Kennesaw State University November 9, 008 Abstract This document is a summary of the theory and techniques used to represent functions

More information

Rolle s Theorem. q( x) = 1

Rolle s Theorem. q( x) = 1 Lecture 1 :The Mean Value Theorem We know that constant functions have derivative zero. Is it possible for a more complicated function to have derivative zero? In this section we will answer this question

More information

Math 3000 Section 003 Intro to Abstract Math Homework 2

Math 3000 Section 003 Intro to Abstract Math Homework 2 Math 3000 Section 003 Intro to Abstract Math Homework 2 Department of Mathematical and Statistical Sciences University of Colorado Denver, Spring 2012 Solutions (February 13, 2012) Please note that these

More information

5. Factoring by the QF method

5. Factoring by the QF method 5. Factoring by the QF method 5.0 Preliminaries 5.1 The QF view of factorability 5.2 Illustration of the QF view of factorability 5.3 The QF approach to factorization 5.4 Alternative factorization by the

More information

Simplify the rational expression. Find all numbers that must be excluded from the domain of the simplified rational expression.

Simplify the rational expression. Find all numbers that must be excluded from the domain of the simplified rational expression. MAC 1105 Final Review Simplify the rational expression. Find all numbers that must be excluded from the domain of the simplified rational expression. 1) 8x 2-49x + 6 x - 6 A) 1, x 6 B) 8x - 1, x 6 x -

More information

We can express this in decimal notation (in contrast to the underline notation we have been using) as follows: 9081 + 900b + 90c = 9001 + 100c + 10b

We can express this in decimal notation (in contrast to the underline notation we have been using) as follows: 9081 + 900b + 90c = 9001 + 100c + 10b In this session, we ll learn how to solve problems related to place value. This is one of the fundamental concepts in arithmetic, something every elementary and middle school mathematics teacher should

More information

The last three chapters introduced three major proof techniques: direct,

The last three chapters introduced three major proof techniques: direct, CHAPTER 7 Proving Non-Conditional Statements The last three chapters introduced three major proof techniques: direct, contrapositive and contradiction. These three techniques are used to prove statements

More information

E3: PROBABILITY AND STATISTICS lecture notes

E3: PROBABILITY AND STATISTICS lecture notes E3: PROBABILITY AND STATISTICS lecture notes 2 Contents 1 PROBABILITY THEORY 7 1.1 Experiments and random events............................ 7 1.2 Certain event. Impossible event............................

More information

Basic Proof Techniques

Basic Proof Techniques Basic Proof Techniques David Ferry dsf43@truman.edu September 13, 010 1 Four Fundamental Proof Techniques When one wishes to prove the statement P Q there are four fundamental approaches. This document

More information

The Dirichlet Unit Theorem

The Dirichlet Unit Theorem Chapter 6 The Dirichlet Unit Theorem As usual, we will be working in the ring B of algebraic integers of a number field L. Two factorizations of an element of B are regarded as essentially the same if

More information

SAT Math Facts & Formulas Review Quiz

SAT Math Facts & Formulas Review Quiz Test your knowledge of SAT math facts, formulas, and vocabulary with the following quiz. Some questions are more challenging, just like a few of the questions that you ll encounter on the SAT; these questions

More information

MATH 150 HOMEWORK 4 SOLUTIONS

MATH 150 HOMEWORK 4 SOLUTIONS MATH 150 HOMEWORK 4 SOLUTIONS Section 1.8 Show tht the product of two of the numbers 65 1000 8 2001 + 3 177, 79 1212 9 2399 + 2 2001, nd 24 4493 5 8192 + 7 1777 is nonnegtive. Is your proof constructive

More information

1.6 The Order of Operations

1.6 The Order of Operations 1.6 The Order of Operations Contents: Operations Grouping Symbols The Order of Operations Exponents and Negative Numbers Negative Square Roots Square Root of a Negative Number Order of Operations and Negative

More information

A three point formula for finding roots of equations by the method of least squares

A three point formula for finding roots of equations by the method of least squares A three point formula for finding roots of equations by the method of least squares Ababu Teklemariam Tiruneh 1 ; William N. Ndlela 1 ; Stanley J. Nkambule 1 1 Lecturer, Department of Environmental Health

More information

Finding Rates and the Geometric Mean

Finding Rates and the Geometric Mean Finding Rates and the Geometric Mean So far, most of the situations we ve covered have assumed a known interest rate. If you save a certain amount of money and it earns a fixed interest rate for a period

More information

Zeros of Polynomial Functions

Zeros of Polynomial Functions Review: Synthetic Division Find (x 2-5x - 5x 3 + x 4 ) (5 + x). Factor Theorem Solve 2x 3-5x 2 + x + 2 =0 given that 2 is a zero of f(x) = 2x 3-5x 2 + x + 2. Zeros of Polynomial Functions Introduction

More information

Aim. Decimal Search. An Excel 'macro' was used to do the calculations. A copy of the script can be found in Appendix A.

Aim. Decimal Search. An Excel 'macro' was used to do the calculations. A copy of the script can be found in Appendix A. Aim The aim of this investigation is to use and compare three different methods of finding specific solutions to polynomials that cannot be solved algebraically. The methods that will be considered are;

More information

3 1. Note that all cubes solve it; therefore, there are no more

3 1. Note that all cubes solve it; therefore, there are no more Math 13 Problem set 5 Artin 11.4.7 Factor the following polynomials into irreducible factors in Q[x]: (a) x 3 3x (b) x 3 3x + (c) x 9 6x 6 + 9x 3 3 Solution: The first two polynomials are cubics, so if

More information

Math 223 Abstract Algebra Lecture Notes

Math 223 Abstract Algebra Lecture Notes Math 223 Abstract Algebra Lecture Notes Steven Tschantz Spring 2001 (Apr. 23 version) Preamble These notes are intended to supplement the lectures and make up for the lack of a textbook for the course

More information

Section IV.1: Recursive Algorithms and Recursion Trees

Section IV.1: Recursive Algorithms and Recursion Trees Section IV.1: Recursive Algorithms and Recursion Trees Definition IV.1.1: A recursive algorithm is an algorithm that solves a problem by (1) reducing it to an instance of the same problem with smaller

More information

it is easy to see that α = a

it is easy to see that α = a 21. Polynomial rings Let us now turn out attention to determining the prime elements of a polynomial ring, where the coefficient ring is a field. We already know that such a polynomial ring is a UF. Therefore

More information

H/wk 13, Solutions to selected problems

H/wk 13, Solutions to selected problems H/wk 13, Solutions to selected problems Ch. 4.1, Problem 5 (a) Find the number of roots of x x in Z 4, Z Z, any integral domain, Z 6. (b) Find a commutative ring in which x x has infinitely many roots.

More information

A Course in Discrete Structures. Rafael Pass Wei-Lung Dustin Tseng

A Course in Discrete Structures. Rafael Pass Wei-Lung Dustin Tseng A Course in Discrete Structures Rafael Pass Wei-Lung Dustin Tseng Preface Discrete mathematics deals with objects that come in discrete bundles, e.g., 1 or 2 babies. In contrast, continuous mathematics

More information

Intermediate Value Theorem, Rolle s Theorem and Mean Value Theorem

Intermediate Value Theorem, Rolle s Theorem and Mean Value Theorem Intermediate Value Theorem, Rolle s Theorem and Mean Value Theorem February 21, 214 In many problems, you are asked to show that something exists, but are not required to give a specific example or formula

More information

Section 1.4. Difference Equations

Section 1.4. Difference Equations Difference Equations to Differential Equations Section 1.4 Difference Equations At this point almost all of our sequences have had explicit formulas for their terms. That is, we have looked mainly at sequences

More information

Taylor and Maclaurin Series

Taylor and Maclaurin Series Taylor and Maclaurin Series In the preceding section we were able to find power series representations for a certain restricted class of functions. Here we investigate more general problems: Which functions

More information

POLYNOMIAL FUNCTIONS

POLYNOMIAL FUNCTIONS POLYNOMIAL FUNCTIONS Polynomial Division.. 314 The Rational Zero Test.....317 Descarte s Rule of Signs... 319 The Remainder Theorem.....31 Finding all Zeros of a Polynomial Function.......33 Writing a

More information

o-minimality and Uniformity in n 1 Graphs

o-minimality and Uniformity in n 1 Graphs o-minimality and Uniformity in n 1 Graphs Reid Dale July 10, 2013 Contents 1 Introduction 2 2 Languages and Structures 2 3 Definability and Tame Geometry 4 4 Applications to n 1 Graphs 6 5 Further Directions

More information

An Introduction to Number Theory Prime Numbers and Their Applications.

An Introduction to Number Theory Prime Numbers and Their Applications. East Tennessee State University Digital Commons @ East Tennessee State University Electronic Theses and Dissertations 8-2006 An Introduction to Number Theory Prime Numbers and Their Applications. Crystal

More information

Solutions Manual for How to Read and Do Proofs

Solutions Manual for How to Read and Do Proofs Solutions Manual for How to Read and Do Proofs An Introduction to Mathematical Thought Processes Sixth Edition Daniel Solow Department of Operations Weatherhead School of Management Case Western Reserve

More information

Chapter 7. Functions and onto. 7.1 Functions

Chapter 7. Functions and onto. 7.1 Functions Chapter 7 Functions and onto This chapter covers functions, including function composition and what it means for a function to be onto. In the process, we ll see what happens when two dissimilar quantifiers

More information

Mathematics Course 111: Algebra I Part IV: Vector Spaces

Mathematics Course 111: Algebra I Part IV: Vector Spaces Mathematics Course 111: Algebra I Part IV: Vector Spaces D. R. Wilkins Academic Year 1996-7 9 Vector Spaces A vector space over some field K is an algebraic structure consisting of a set V on which are

More information

Chapter 13: Basic ring theory

Chapter 13: Basic ring theory Chapter 3: Basic ring theory Matthew Macauley Department of Mathematical Sciences Clemson University http://www.math.clemson.edu/~macaule/ Math 42, Spring 24 M. Macauley (Clemson) Chapter 3: Basic ring

More information

Recursive Algorithms. Recursion. Motivating Example Factorial Recall the factorial function. { 1 if n = 1 n! = n (n 1)! if n > 1

Recursive Algorithms. Recursion. Motivating Example Factorial Recall the factorial function. { 1 if n = 1 n! = n (n 1)! if n > 1 Recursion Slides by Christopher M Bourke Instructor: Berthe Y Choueiry Fall 007 Computer Science & Engineering 35 Introduction to Discrete Mathematics Sections 71-7 of Rosen cse35@cseunledu Recursive Algorithms

More information

The Characteristic Polynomial

The Characteristic Polynomial Physics 116A Winter 2011 The Characteristic Polynomial 1 Coefficients of the characteristic polynomial Consider the eigenvalue problem for an n n matrix A, A v = λ v, v 0 (1) The solution to this problem

More information

Catalan Numbers. Thomas A. Dowling, Department of Mathematics, Ohio State Uni- versity.

Catalan Numbers. Thomas A. Dowling, Department of Mathematics, Ohio State Uni- versity. 7 Catalan Numbers Thomas A. Dowling, Department of Mathematics, Ohio State Uni- Author: versity. Prerequisites: The prerequisites for this chapter are recursive definitions, basic counting principles,

More information

Application. Outline. 3-1 Polynomial Functions 3-2 Finding Rational Zeros of. Polynomial. 3-3 Approximating Real Zeros of.

Application. Outline. 3-1 Polynomial Functions 3-2 Finding Rational Zeros of. Polynomial. 3-3 Approximating Real Zeros of. Polynomial and Rational Functions Outline 3-1 Polynomial Functions 3-2 Finding Rational Zeros of Polynomials 3-3 Approximating Real Zeros of Polynomials 3-4 Rational Functions Chapter 3 Group Activity:

More information

6 EXTENDING ALGEBRA. 6.0 Introduction. 6.1 The cubic equation. Objectives

6 EXTENDING ALGEBRA. 6.0 Introduction. 6.1 The cubic equation. Objectives 6 EXTENDING ALGEBRA Chapter 6 Extending Algebra Objectives After studying this chapter you should understand techniques whereby equations of cubic degree and higher can be solved; be able to factorise

More information

Ex. 2.1 (Davide Basilio Bartolini)

Ex. 2.1 (Davide Basilio Bartolini) ECE 54: Elements of Information Theory, Fall 00 Homework Solutions Ex.. (Davide Basilio Bartolini) Text Coin Flips. A fair coin is flipped until the first head occurs. Let X denote the number of flips

More information

Applications of Fermat s Little Theorem and Congruences

Applications of Fermat s Little Theorem and Congruences Applications of Fermat s Little Theorem and Congruences Definition: Let m be a positive integer. Then integers a and b are congruent modulo m, denoted by a b mod m, if m (a b). Example: 3 1 mod 2, 6 4

More information

2 When is a 2-Digit Number the Sum of the Squares of its Digits?

2 When is a 2-Digit Number the Sum of the Squares of its Digits? When Does a Number Equal the Sum of the Squares or Cubes of its Digits? An Exposition and a Call for a More elegant Proof 1 Introduction We will look at theorems of the following form: by William Gasarch

More information

The Open University s repository of research publications and other research outputs

The Open University s repository of research publications and other research outputs Open Research Online The Open University s repository of research publications and other research outputs The degree-diameter problem for circulant graphs of degree 8 and 9 Journal Article How to cite:

More information

Near Optimal Solutions

Near Optimal Solutions Near Optimal Solutions Many important optimization problems are lacking efficient solutions. NP-Complete problems unlikely to have polynomial time solutions. Good heuristics important for such problems.

More information

Diagonalization. Ahto Buldas. Lecture 3 of Complexity Theory October 8, 2009. Slides based on S.Aurora, B.Barak. Complexity Theory: A Modern Approach.

Diagonalization. Ahto Buldas. Lecture 3 of Complexity Theory October 8, 2009. Slides based on S.Aurora, B.Barak. Complexity Theory: A Modern Approach. Diagonalization Slides based on S.Aurora, B.Barak. Complexity Theory: A Modern Approach. Ahto Buldas Ahto.Buldas@ut.ee Background One basic goal in complexity theory is to separate interesting complexity

More information

ELEMENTARY PROBLEMS AND SOLUTIONS. Edited by A. P. HiLLMAN University of New Mexico, Albuquerque, NM 87131

ELEMENTARY PROBLEMS AND SOLUTIONS. Edited by A. P. HiLLMAN University of New Mexico, Albuquerque, NM 87131 ELEMENTARY PROBLEMS AND SOLUTIONS Edited by A. P. HiLLMAN University of New Mexico, Albuquerque, NM 87131 Send all communications regarding ELEMENTARY PROBLEMS AND SOLUTIONS to PROFESSOR A. P. HILLMAN,

More information

LINEAR INEQUALITIES. Mathematics is the art of saying many things in many different ways. MAXWELL

LINEAR INEQUALITIES. Mathematics is the art of saying many things in many different ways. MAXWELL Chapter 6 LINEAR INEQUALITIES 6.1 Introduction Mathematics is the art of saying many things in many different ways. MAXWELL In earlier classes, we have studied equations in one variable and two variables

More information

DEGREES OF ORDERS ON TORSION-FREE ABELIAN GROUPS

DEGREES OF ORDERS ON TORSION-FREE ABELIAN GROUPS DEGREES OF ORDERS ON TORSION-FREE ABELIAN GROUPS ASHER M. KACH, KAREN LANGE, AND REED SOLOMON Abstract. We construct two computable presentations of computable torsion-free abelian groups, one of isomorphism

More information

6.4 Special Factoring Rules

6.4 Special Factoring Rules 6.4 Special Factoring Rules OBJECTIVES 1 Factor a difference of squares. 2 Factor a perfect square trinomial. 3 Factor a difference of cubes. 4 Factor a sum of cubes. By reversing the rules for multiplication

More information

MOP 2007 Black Group Integer Polynomials Yufei Zhao. Integer Polynomials. June 29, 2007 Yufei Zhao yufeiz@mit.edu

MOP 2007 Black Group Integer Polynomials Yufei Zhao. Integer Polynomials. June 29, 2007 Yufei Zhao yufeiz@mit.edu Integer Polynomials June 9, 007 Yufei Zhao yufeiz@mit.edu We will use Z[x] to denote the ring of polynomials with integer coefficients. We begin by summarizing some of the common approaches used in dealing

More information

In mathematics, it is often important to get a handle on the error term of an approximation. For instance, people will write

In mathematics, it is often important to get a handle on the error term of an approximation. For instance, people will write Big O notation (with a capital letter O, not a zero), also called Landau's symbol, is a symbolism used in complexity theory, computer science, and mathematics to describe the asymptotic behavior of functions.

More information

SPERNER S LEMMA AND BROUWER S FIXED POINT THEOREM

SPERNER S LEMMA AND BROUWER S FIXED POINT THEOREM SPERNER S LEMMA AND BROUWER S FIXED POINT THEOREM ALEX WRIGHT 1. Intoduction A fixed point of a function f from a set X into itself is a point x 0 satisfying f(x 0 ) = x 0. Theorems which establish the

More information

MATH 289 PROBLEM SET 4: NUMBER THEORY

MATH 289 PROBLEM SET 4: NUMBER THEORY MATH 289 PROBLEM SET 4: NUMBER THEORY 1. The greatest common divisor If d and n are integers, then we say that d divides n if and only if there exists an integer q such that n = qd. Notice that if d divides

More information

Squaring, Cubing, and Cube Rooting

Squaring, Cubing, and Cube Rooting Squaring, Cubing, and Cube Rooting Arthur T. Benjamin Harvey Mudd College Claremont, CA 91711 benjamin@math.hmc.edu I still recall my thrill and disappointment when I read Mathematical Carnival [4], by

More information

Algebra Practice Problems for Precalculus and Calculus

Algebra Practice Problems for Precalculus and Calculus Algebra Practice Problems for Precalculus and Calculus Solve the following equations for the unknown x: 1. 5 = 7x 16 2. 2x 3 = 5 x 3. 4. 1 2 (x 3) + x = 17 + 3(4 x) 5 x = 2 x 3 Multiply the indicated polynomials

More information

Probability: Terminology and Examples Class 2, 18.05, Spring 2014 Jeremy Orloff and Jonathan Bloom

Probability: Terminology and Examples Class 2, 18.05, Spring 2014 Jeremy Orloff and Jonathan Bloom Probability: Terminology and Examples Class 2, 18.05, Spring 2014 Jeremy Orloff and Jonathan Bloom 1 Learning Goals 1. Know the definitions of sample space, event and probability function. 2. Be able to

More information

FACTORING POLYNOMIALS IN THE RING OF FORMAL POWER SERIES OVER Z

FACTORING POLYNOMIALS IN THE RING OF FORMAL POWER SERIES OVER Z FACTORING POLYNOMIALS IN THE RING OF FORMAL POWER SERIES OVER Z DANIEL BIRMAJER, JUAN B GIL, AND MICHAEL WEINER Abstract We consider polynomials with integer coefficients and discuss their factorization

More information

Alex, I will take congruent numbers for one million dollars please

Alex, I will take congruent numbers for one million dollars please Alex, I will take congruent numbers for one million dollars please Jim L. Brown The Ohio State University Columbus, OH 4310 jimlb@math.ohio-state.edu One of the most alluring aspectives of number theory

More information

Rational Exponents. Squaring both sides of the equation yields. and to be consistent, we must have

Rational Exponents. Squaring both sides of the equation yields. and to be consistent, we must have 8.6 Rational Exponents 8.6 OBJECTIVES 1. Define rational exponents 2. Simplify expressions containing rational exponents 3. Use a calculator to estimate the value of an expression containing rational exponents

More information

ALGEBRAIC APPROACH TO COMPOSITE INTEGER FACTORIZATION

ALGEBRAIC APPROACH TO COMPOSITE INTEGER FACTORIZATION ALGEBRAIC APPROACH TO COMPOSITE INTEGER FACTORIZATION Aldrin W. Wanambisi 1* School of Pure and Applied Science, Mount Kenya University, P.O box 553-50100, Kakamega, Kenya. Shem Aywa 2 Department of Mathematics,

More information

1 Sets and Set Notation.

1 Sets and Set Notation. LINEAR ALGEBRA MATH 27.6 SPRING 23 (COHEN) LECTURE NOTES Sets and Set Notation. Definition (Naive Definition of a Set). A set is any collection of objects, called the elements of that set. We will most

More information

U.C. Berkeley CS276: Cryptography Handout 0.1 Luca Trevisan January, 2009. Notes on Algebra

U.C. Berkeley CS276: Cryptography Handout 0.1 Luca Trevisan January, 2009. Notes on Algebra U.C. Berkeley CS276: Cryptography Handout 0.1 Luca Trevisan January, 2009 Notes on Algebra These notes contain as little theory as possible, and most results are stated without proof. Any introductory

More information

The sum of digits of polynomial values in arithmetic progressions

The sum of digits of polynomial values in arithmetic progressions The sum of digits of polynomial values in arithmetic progressions Thomas Stoll Institut de Mathématiques de Luminy, Université de la Méditerranée, 13288 Marseille Cedex 9, France E-mail: stoll@iml.univ-mrs.fr

More information