SAMPLE College Math

‭THE ULTIMATE‬ ‭CREDIT-BY-EXAM‬ ‭STUDY GUIDE FOR:‬ ‭College Math‬ ‭2‬ ‭nd‬ ‭Edition‬

‭12/01/2023‬

‭Acknowledgements‬ ‭We‬‭would‬‭like‬‭to‬‭thank‬‭the‬‭author‬‭for‬‭their‬‭patience,‬‭support,‬‭and‬‭expertise‬‭in‬‭contributing‬‭to‬‭this‬ ‭study‬‭guide;‬‭and‬‭our‬‭editors‬‭for‬‭their‬‭invaluable‬‭efforts‬‭in‬‭reading‬‭and‬‭editing‬‭the‬‭text.‬‭We‬‭would‬ ‭also‬ ‭like‬ ‭to‬ ‭thank‬ ‭those‬ ‭at‬ ‭Achieve‬ ‭Test‬ ‭Prep‬ ‭whose‬ ‭hard‬ ‭work‬ ‭and‬ ‭dedication‬ ‭to‬ ‭fulfilling‬ ‭this‬ ‭project‬ ‭did‬ ‭not‬ ‭go‬ ‭unnoticed.‬‭Lastly,‬‭we‬‭would‬‭like‬‭to‬‭thank‬‭the‬‭Achieve‬‭Test‬‭Prep‬‭students‬‭who‬ ‭have contributed to the growth of these materials over the years.‬

‭This study guide is subject to copyright‬

‭Copyright © 2023 by Achieve‬ ‭All‬ ‭rights‬ ‭reserved.‬ ‭This‬ ‭book‬ ‭or‬ ‭any‬ ‭portion‬ ‭thereof‬ ‭may‬ ‭not‬ ‭be‬ ‭reproduced‬ ‭or‬ ‭used‬ ‭in‬ ‭any‬ ‭manner‬ ‭whatsoever‬ ‭without‬ ‭the‬ ‭express‬ ‭written‬ ‭permission‬ ‭of‬ ‭the‬ ‭publisher‬ ‭except‬ ‭for‬ ‭the‬ ‭use‬ ‭of‬ ‭brief‬ ‭quotations in a book review.‬

‭Printed in the United States of America‬

‭First Printing, 2020‬

‭Achieve‬ ‭PO Box 10188 #29831‬ ‭Newark, NJ 07101-3188‬ ‭Tel: 888.900.8380‬ ‭Visit the Achieve website at‬‭http://www.achievetestprep.com/student‬‭for more information.‬

‭Contents‬

‭Chapter 1:‬ ‭Introduction to Algebra and Functions‬

‭1‬

‭A. Set of Real Numbers‬

‭1‬ ‭3‬ ‭4‬ ‭5‬ ‭5‬ ‭6‬ ‭7‬ ‭7‬

‭B. Inequalities‬

‭C. Mathematical Translations of Equalities from Words‬ ‭D. Mathematical Translations of Inequalities from Words‬

‭E. Solving Equations‬ ‭F. Solving Inequalities‬

‭G. Solving Inequalities with Modulus Symbol‬

‭H. Systems of Linear Equations‬

‭I. Polynomials‬

‭12‬ ‭13‬ ‭14‬ ‭16‬ ‭17‬ ‭19‬ ‭22‬ ‭26‬ ‭27‬ ‭28‬ ‭29‬ ‭29‬ ‭29‬ ‭30‬ ‭31‬ ‭32‬ ‭32‬ ‭33‬ ‭34‬ ‭36‬ ‭38‬ ‭41‬ ‭42‬ ‭44‬ ‭45‬ ‭26‬ ‭38‬

‭J. Solving Quadratic Equations‬

‭K. Functions‬

‭L. Exponential Functions‬ ‭M. Logarithm Functions‬ ‭Chapter 1: Review Questions‬ ‭Chapter 1: Review Answers‬

‭Chapter 2:‬ ‭Financial Mathematics‬

‭A. Percent‬

‭B. Discounts, Markups, and Taxation‬

‭C. Change in Percentage‬ ‭D. Profits and Losses‬

‭E. Interest‬

‭F. Simple Interest‬

‭G. Compound Interest‬ ‭H. Continuous Interest‬

‭I. Effective Interest Rate (Effective Annual Rate of Interest or EAR)‬

‭J. Effective Annual Yield/Annual Percentage Rate (APR)‬

‭K. Present and Future Value‬ ‭Chapter 2: Review Questions‬ ‭Chapter 2: Review Answers‬

‭Chapter 3:‬ ‭Geometry‬

‭A. Triangles‬

‭B. Quadrilaterals‬

‭C. Parallel and Perpendicular Lines‬

‭D. Circles‬

‭E. Theorems of Circle‬

‭Chapter 3: Review Questions‬ ‭Chapter 3: Review Answers‬

‭47‬ ‭49‬

‭Chapter 4:‬ ‭Counting and Probability‬

‭53‬

‭A. Counting‬

‭53‬ ‭54‬ ‭55‬ ‭56‬ ‭56‬ ‭57‬ ‭58‬ ‭59‬ ‭60‬ ‭61‬ ‭61‬ ‭63‬ ‭66‬ ‭70‬ ‭70‬ ‭72‬ ‭74‬ ‭74‬ ‭75‬ ‭76‬ ‭77‬ ‭77‬ ‭78‬ ‭79‬ ‭82‬ ‭84‬ ‭85‬ ‭85‬ ‭85‬ ‭85‬ ‭86‬ ‭87‬ ‭70‬ ‭84‬

‭B. Fundamental Counting Principle‬

‭C. Permutations‬

‭D. Distinguishable Permutations‬

‭E. Combinations‬

‭F. Probability‬

‭G. Complement of an Event‬ ‭H. Mutually Exclusive Events‬

‭I. Intersection of Independent Events‬

‭J. Expected Value‬

‭K. Conditional Probability‬ ‭Chapter 4: Review Questions‬ ‭Chapter 4: Review Answers‬

‭Chapter 5:‬ ‭Data Analysis and Statistics‬

‭A. Data Interpretation‬

‭B. Data Tables‬ ‭C. Bar Graph‬ ‭D. Line Graphs‬ ‭E. Pie Charts‬

‭F. Measures of Central Tendency and Measures of Dispersion‬

‭G. Mean‬

‭H. Median‬

‭I. Mode‬

‭J. Standard Deviation and Variance‬ ‭Chapter 5: Review Questions‬

‭Chapter 5: Review Answers‬

‭Chapter 6:‬ ‭Logic and Sets‬

‭A. Logical Operations and Statements‬

‭B. Negation‬

‭C. Conjunction‬ ‭D. Disjunction‬ ‭E. Parentheses‬

‭F. Truth Values and Truth Tables‬

‭G. Conditional Statements‬

‭H. Logical Equivalence‬

‭87‬ ‭87‬ ‭88‬ ‭91‬ ‭92‬ ‭95‬ ‭96‬ ‭99‬

‭I. Converse, Inverse, and Contrapositive‬

‭J. Logical Arguments‬

‭K. Sets‬

‭L. Operations on Sets‬ ‭M. Cartesian Products‬

‭Chapter 6: Review Questions‬ ‭Chapter 6: Review Answers‬

‭Chapter 1:‬ ‭Introduction to Algebra and Functions‬

‭Overview‬ ‭Mathematics‬ ‭is‬‭a‬‭common‬‭tool‬‭that‬‭is‬‭used‬‭in‬‭everyday‬‭life.‬‭Ranging‬‭from‬‭simple‬‭counting‬‭of‬‭inventory‬ ‭items‬ ‭to‬ ‭solving‬ ‭complex‬ ‭equations‬ ‭in‬ ‭computer‬ ‭and‬ ‭engineering‬ ‭work,‬ ‭every‬ ‭day‬ ‭involves‬ ‭the‬ ‭use‬‭of‬ ‭mathematics.‬‭There‬‭are‬‭a‬‭large‬‭number‬‭of‬‭incentives‬‭for‬‭an‬‭individual‬‭to‬‭study‬‭throughout‬‭this‬‭course‬‭to‬ ‭equip‬ ‭him/herself‬ ‭with‬ ‭the‬ ‭knowledge‬ ‭of‬ ‭mathematics‬ ‭in‬ ‭order‬ ‭to‬ ‭excel‬ ‭in‬ ‭their‬ ‭career.‬ ‭Mathematics‬ ‭provides‬‭us‬‭with‬‭a‬‭better‬‭understanding‬‭of‬‭the‬‭world‬‭around‬‭us.‬‭It‬‭helps‬‭to‬‭hone‬‭the‬‭individual’s‬‭skills‬‭in‬ ‭problem‬ ‭solving,‬ ‭logical‬ ‭reasoning‬ ‭and‬ ‭flexible‬ ‭thinking,‬ ‭which‬ ‭is‬ ‭of‬‭utmost‬‭importance‬‭in‬‭the‬‭modern‬ ‭business‬‭world.‬‭It‬‭is‬‭pervasive‬‭and‬‭useful‬‭in‬‭almost‬‭all‬‭the‬‭arenas‬‭of‬‭life,‬‭such‬‭as‬‭business‬‭management,‬ ‭predicting‬ ‭stock‬ ‭market‬ ‭prices,‬ ‭safeguarding‬ ‭credit‬ ‭transactions‬ ‭on‬ ‭the‬ ‭internet,‬‭science,‬‭engineering,‬ ‭and even managing day-to-day financial activities.‬ ‭In‬ ‭this‬ ‭chapter,‬ ‭the‬ ‭introduction‬ ‭to‬ ‭algebra‬‭and‬‭functions‬‭will‬‭be‬‭presented.‬‭The‬‭main‬‭focus‬‭will‬‭be‬‭on‬ ‭concept‬ ‭building‬ ‭and‬ ‭its‬ ‭application.‬‭The‬‭building‬‭blocks‬‭of‬‭this‬‭chapter‬‭will‬‭include‬‭solving‬‭equations,‬ ‭linear‬‭inequalities,‬‭systems‬‭of‬‭linear‬‭equations‬‭by‬‭analytical‬‭and‬‭graphical‬‭methods,‬‭functions,‬‭and‬‭linear‬ ‭and‬ ‭exponential‬ ‭growth.‬‭The‬‭aim‬‭of‬‭this‬‭chapter‬‭is‬‭to‬‭equip‬‭you‬‭with‬‭the‬‭knowledge‬‭of‬‭general‬‭algebra‬ ‭that helps in building the foundation of mathematics.‬ ‭Objectives‬ ‭A. Set of Real Numbers‬ ‭Algebra‬‭is‬‭a‬‭tool‬‭that‬‭is‬‭used‬‭to‬‭solve‬‭real‬‭life‬‭problems‬‭in‬‭the‬‭domains‬‭of‬‭science,‬‭business,‬‭architecture,‬ ‭management,‬ ‭space‬ ‭travel,‬ ‭and‬ ‭many‬ ‭other‬ ‭fields.‬ ‭We‬ ‭begin‬ ‭this‬ ‭chapter‬ ‭by‬ ‭understanding‬ ‭the‬ ‭basic‬ ‭notations and symbols used to build and solve algebraic expressions.‬ ‭Sets‬ ‭represent‬ ‭the‬ ‭collection‬ ‭of‬ ‭similar‬ ‭elements,‬ ‭and‬ ‭are‬ ‭denoted‬ ‭by‬ ‭the‬ ‭enclosed‬ ‭brackets‬ ‭{}.‬ ‭The‬ ‭unique‬‭characteristic‬‭of‬‭all‬‭elements‬‭in‬‭a‬‭set‬‭is‬‭that‬‭they‬‭have‬‭some‬‭similarity‬‭in‬‭appearance‬‭of‬‭purpose.‬ ‭For‬‭instance,‬‭{2,‬‭4,‬‭6,‬‭8}‬‭represents‬‭the‬‭set‬‭of‬‭all‬‭one-digit‬‭even‬‭numbers,‬‭and‬‭{a,‬‭e,‬‭i,‬‭o,‬‭u}‬‭represents‬‭the‬ ‭set‬‭of‬‭all‬‭vowels‬‭in‬‭English.‬‭Sets‬‭are‬‭denoted‬‭by‬‭a‬‭letter.‬‭The‬‭set‬‭of‬‭all‬‭positive‬‭numbers‬‭less‬‭than‬‭10‬‭is‬ ‭denoted‬‭by‬‭S‬‭=‬‭{1,‬‭2,‬‭3,‬‭4,‬‭5,‬‭6,‬‭7,‬‭8,‬‭9}‬‭and‬‭the‬‭set‬‭of‬‭all‬‭odd‬‭numbers‬‭less‬‭than‬‭10‬‭is‬‭denoted‬‭by‬‭T=‬‭{1,‬ ‭3,‬‭5,‬‭7,‬‭9}.‬‭In‬‭this‬‭case,‬‭T‬‭is‬‭known‬‭as‬‭the‬‭sub-set‬‭of‬‭S,‬‭since‬‭all‬‭elements‬‭in‬‭set‬‭T‬‭are‬‭present‬‭in‬‭set‬‭S.‬ ‭Another‬ ‭way‬ ‭to‬ ‭describe‬ ‭a‬ ‭set‬ ‭is‬ ‭by‬ ‭using‬ ‭a‬ ‭set-builder‬ ‭notation.‬ ‭For‬ ‭instance,‬ ‭the‬ ‭set‬ ‭{1,‬ ‭3,‬ ‭5}‬ ‭in‬ ‭a‬ ‭set-builder‬‭notation‬‭is‬‭written‬‭as‬‭{x‬‭l‬‭x‬‭is‬‭an‬‭odd‬‭number‬‭between‬‭0‬‭and‬‭6}.‬‭Set-builder‬‭notation‬‭is‬‭read‬ ‭as follows:‬ ‭By the end of this chapter, you should be able to recognize, understand, and solve the following:‬ ‭●‬ ‭Algebraic operations‬ ‭●‬ ‭Equations and inequalities‬ ‭●‬ ‭Functions and their properties‬ ‭●‬ ‭Number systems and operations‬

‭© 2023 ACHIEVE ULTIMATE CREDIT-BY-EXAM GUIDE‬‭|‬‭COLLEGE MATH‬

‭1‬

‭Real‬ ‭numbers‬ ‭are‬ ‭used‬ ‭extensively‬ ‭in‬ ‭mathematics‬‭and‬‭are‬‭represented‬‭on‬‭a‬‭continuous‬‭number‬‭line.‬ ‭The‬‭number‬‭line‬‭includes‬‭the‬‭set‬‭of‬‭all‬‭the‬‭whole‬‭numbers‬‭{0,‬‭1,‬‭2,‬‭3,‬‭4…},‬‭natural‬‭numbers{1,‬‭2,‬‭3,‬‭4…},‬ ‭integers‬‭{…-3,‬‭-2,‬‭-1,‬‭0,‬‭1,‬‭2,‬‭3,‬‭…},‬‭fractions‬‭(numbers‬‭written‬‭in‬‭the‬‭form‬‭of‬ ‭,‬‭such‬‭that‬‭the‬‭ratio‬‭is‬‭not‬ ‭ ‭ ‬ ‬ ‭equal‬‭to‬‭zero)‬‭and‬‭irrational‬‭numbers‬‭(like‬‭square‬‭root‬‭of‬‭2,‬‭given‬‭by‬ ‭).‬‭On‬‭the‬‭number‬‭line,‬‭negative‬ ‭2‬ ‭values are on the left side of zero while positive values are on the right side of zero, as shown below:‬ ‭The‬ ‭properties‬ ‭of‬ ‭real‬ ‭numbers‬ ‭deal‬ ‭with‬ ‭four‬ ‭major‬ ‭operations:‬ ‭addition‬ ‭(+),‬ ‭subtraction‬ ‭(‬ ‭),‬ − ‭multiplication‬ ‭(‬ ‭)‬ ‭and‬ ‭division‬ ‭(‬ ‭).‬ ‭Addition,‬ ‭subtraction,‬ ‭and‬ ‭multiplication‬ ‭of‬ ‭real‬ ‭numbers‬ ‭will‬ ‭×‬, ‭‬‭∙‬ ‭÷‬, ‭‬‭/‬ ‭result‬ ‭in‬‭a‬‭real‬‭number.‬‭Division‬‭of‬‭real‬‭numbers‬‭is‬‭also‬‭possible,‬‭provided‬‭that‬‭the‬‭denominator‬‭of‬‭the‬ ‭fraction is not equal to zero. If the denominator is equal to zero, then the result is undefined.‬ ‭The Properties of Real Number are listed below (assume‬ ‭,‬ ‭, and‬ ‭are real numbers):‬ ‭‬‭ ‬ ‭‬‭ ‬ ‭ ‬ ‭1.‬ ‭Cumulative‬ ‭law‬ ‭states‬ ‭that‬ ‭when‬ ‭we‬ ‭add‬ ‭or‬ ‭multiply‬ ‭two‬ ‭real‬ ‭numbers,‬ ‭their‬ ‭order‬ ‭does‬ ‭not‬ ‭matter. That is,‬ ‭and‬ ‭ ‬ + ‭ ‬ = ‭ ‬ + ‭ ‬‭‬ ‭ ‬‭×‬‭ ‬‭‬ = ‭‬‭ ‬‭×‬‭ ‬ ‭2.‬ ‭Associative‬ ‭law‬ ‭states‬ ‭that‬ ‭while‬ ‭adding‬ ‭or‬ ‭multiplying‬ ‭more‬ ‭than‬ ‭two‬ ‭real‬ ‭numbers‬ ‭then‬‭the‬ ‭effect‬ ‭of‬ ‭parentheses‬ ‭does‬ ‭not‬ ‭matter.‬ ‭That‬ ‭is,‬ ‭and‬ (‭ ‬ + ‭ ‬) + ‭ ‬ = ‭ ‬ + (‭ ‬ + ‭ ‬) (‭ ‬‭×‬‭ ‬)‭×‬‭ ‬ = ‭‬‭ ‬‭×‬(‭ ‬‭×‬‭ ‬) ‭3.‬ ‭Distributive‬ ‭law‬ ‭applies‬ ‭to‬ ‭the‬ ‭cases‬‭where‬‭one‬‭makes‬‭use‬‭of‬‭both‬‭addition‬‭and‬‭multiplication‬ ‭operations.‬ ‭and‬ ‭ ‬‭×‬(‭ ‬ + ‭ ‬) = ‭ ‬‭×‬‭ ‬ + ‭ ‭×‬ ‬‭ ‬ (‭ ‬ + ‭ ‬)‭×‬‭ ‬ = ‭ ‬‭×‬‭ ‬ + ‭ ‬‭×‬‭ ‬ ‭4.‬ ‭The‬ ‭additive‬ ‭identity‬ ‭is‬ ‭known‬ ‭as‬ ‭0‬ ‭and‬ ‭1‬ ‭is‬ ‭a‬ ‭multiplicative‬ ‭identity.‬ ‭That‬ ‭is,‬ ‭and‬ ‭ ‬ + ‭0‬ = ‭ ‬ ‭ ‬‭×1‬ = ‭ ‬ ‭5.‬ ‭Additive‬‭inverse‬‭is‬‭denoted‬‭by‬‭a‬‭negative‬‭sign.‬‭That‬‭is,‬‭the‬‭additive‬‭inverse‬‭of‬ ‭would‬‭be‬‭(‬ ‭).‬ ‭ ‬ − ‭ ‬ ‭Addition of a real number with its additive inverse would be 0. So,‬ ‭‬‭ ‬‭‬ + ‭‬(− ‭ ‬)‭‬ = ‭‬‭0‬ ‭6.‬ ‭Multiplicative‬ ‭inverse‬ ‭of‬ ‭would‬ ‭be‬ ‭-1‬ ‭or‬ ‭.‬ ‭The‬ ‭multiplication‬ ‭of‬ ‭a‬ ‭real‬ ‭number‬ ‭with‬ ‭its‬ ‭ ‬ ‭ ‬ −‭1‬ ‭ ‭1 ‬ ‬ ‭multiplicative inverse would be equal to 1, Therefore,‬ ‭ ‬‭×‬‭ ‬ −‭1‬ = ‭1‬ ‭7.‬ ‭Cancellation law for addition: if‬ ‭, then‬ ‭.‬ ‭ ‬ + ‭ ‬ = ‭ ‬ + ‭ ‬ ‭ ‬= ‭ ‬ ‭8.‬ ‭Cancellation law for multiplication: if‬ ‭, then‬ ‭, such that‬ ‭.‬ ‭ ‬‭×‬‭ ‬ = ‭ ‬‭×‬‭ ‬ ‭ ‬= ‭ ‬ ‭ ‬‭≠0‬ ‭9.‬ ‭Cancellation law for division:‬ ‭, provided‬ ‭and‬ ‭.‬ ‭ ‭ ‬‬ = ‭ ‭ ‬ ‬ ‭ ‬‭≠0‬ ‭ ‬‭≠0‬ ‭Absolute‬ ‭values,‬ ‭or‬ ‭the‬ ‭magnitude‬ ‭of‬ ‭an‬ ‭integer,‬ ‭are‬ ‭another‬ ‭vital‬ ‭concept‬ ‭to‬ ‭know‬ ‭in‬ ‭algebra.‬ ‭It‬ ‭is‬ ‭defined‬‭as‬‭the‬‭distance‬‭between‬‭the‬‭integer‬‭and‬‭the‬‭zero‬‭value‬‭on‬‭the‬‭number‬‭line.‬‭Absolute‬‭values‬‭are‬ ‭denoted‬ ‭by‬ ‭the‬ ‭modulus‬ ‭symbol‬ ‭where‬ ‭can‬ ‭be‬ ‭any‬ ‭integer,‬ ‭negative‬ ‭or‬ ‭positive.‬ ‭If‬ ‭we‬ ‭have‬ ‭to‬ |‭ ‬| ‭ ‬

‭© 2023 ACHIEVE ULTIMATE CREDIT-BY-EXAM GUIDE‬‭|‬‭COLLEGE MATH‬

‭2‬

‭calculate‬ ‭the‬ ‭absolute‬ ‭value‬ ‭of‬ ‭-5,‬ ‭then‬ ‭it‬ ‭will‬ ‭be‬ ‭denoted‬ ‭by‬ ‭|-5|and‬ ‭is‬ ‭equal‬ ‭to‬ ‭5,‬ ‭showing‬ ‭that‬ ‭the‬ ‭distance from -5 to 0 is 5 units. Some of the properties of absolute values are:‬ | ‭ ‬| = {‭ ‬ ‭ ‬‭ ‬‭≥0‬ − ‭ ‬ ( )‭‬‭ ‬‭‬‭ ‬ < ‭0‬ || −‭ ‬ |‭ ‭≥‬‭ ‬| 0=‬ ‭ ‬| ‭ ‬‭ ‬‭ ‬| | ‭ ‬ * ‭ ‬| = ‭‬|‭‬‭ ‬‭‬| * |‭‬‭ ‬‭‬| ‭Scientific Notation‬ ‭Sometimes‬‭we‬‭make‬‭use‬‭of‬‭some‬‭power‬‭of‬‭10‬‭that‬‭makes‬‭it‬‭convenient‬‭to‬‭write‬‭a‬‭very‬‭large‬‭number;‬‭this‬ ‭means‬ ‭we‬ ‭are‬ ‭making‬ ‭use‬ ‭of‬ ‭scientific‬ ‭notation.‬ ‭For‬ ‭instance,‬ ‭suppose‬ ‭we‬ ‭have‬ ‭to‬ ‭write‬ ‭the‬ ‭number‬ ‭687657.788. We can write it as‬ ‭.‬ ‭6‬. ‭87657788×‬‭10‬ ‭5‬ ‭B. Inequalities‬ ‭The‬ ‭value‬ ‭of‬ ‭different‬ ‭numbers‬ ‭can‬ ‭be‬ ‭compared‬ ‭by‬ ‭their‬ ‭relative‬ ‭position‬ ‭on‬ ‭the‬ ‭number‬ ‭line.‬ ‭For‬ ‭instance, in the given number line below,‬

‭ ‬ ‭ ‬

‭ ‬‭‬ < ‭‬‭ ‬

‭ ‬

‭ ‬

‭is‬‭less‬‭than‬ ‭and‬‭is‬‭denoted‬‭by‬ ‭also‬ ‭say‬ ‭,‬ ‭that‬ ‭is‬ ‭is‬‭greater‬‭than‬ ‭and‬‭lies‬‭on‬‭the‬‭right‬‭side‬‭of‬‭the‬‭number‬‭line,‬‭relative‬‭to‬‭the‬ ‭ ‬‭‬ > ‭‬‭ ‬ ‭ ‬ ‭ ‬ ‭position of‬ ‭.‬ ‭ ‬ ‭The mathematical representation for different expressions is given in the following table:‬ ‭,‬‭which‬‭means‬ ‭lies‬‭to‬‭the‬‭left‬‭of‬ ‭on‬‭the‬‭number‬‭line.‬‭We‬‭can‬

‭ ‬ = ‭‬‭ ‬ ‭ ‬ < ‭‬‭ ‬ ‭ ‬ > ‭‬‭ ‬ ‭ ‬‭≥‬‭ ‬ ‭ ‬‭≤‬‭ ‬ ‭ ‬‭≠‬‭ ‬ ‭ ‬‭≈‬‭ ‬

‭Interpretations‬ ‭is equal to‬ ‭ ‬ ‭ ‬ ‭is less than‬ ‭ ‬ ‭ ‬ ‭is greater than‬ ‭ ‬ ‭ ‬ ‭is greater than or equal to‬ ‭ ‬ ‭ ‬ ‭is less than or equal to‬ ‭ ‬ ‭ ‬ ‭is not equal to‬ ‭ ‬ ‭ ‬

‭Expressions‬

‭is approximately equal to‬ ‭ ‬ ‭ ‬ ‭The‬ ‭symbols‬ ‭<,‬ ‭>,‬ ‭≥,‬‭≤‬‭and‬‭≠‬‭denote‬‭the‬‭signs‬‭of‬‭inequalities‬‭and‬‭the‬‭expressions‬‭using‬‭these‬‭signs‬‭of‬ ‭inequalities,‬ ‭,‬ ‭,‬ ‭,‬ ‭and‬ ‭denotes‬ ‭inequalities.‬ ‭We‬ ‭can‬ ‭make‬ ‭use‬ ‭of‬ ‭set-builder‬ ‭ ‬ < ‭ ‬ ‭ ‬ > ‭ ‬ ‭ ‬‭≥‬‭ ‬ ‭ ‬‭≤‬‭ ‬ ‭ ‬‭≠‬‭ ‬ ‭notation‬‭for‬‭these‬‭inequalities‬‭as‬‭well.‬‭For‬‭instance,‬ ‭means‬‭set‬ ‭represents‬‭all‬‭the‬‭values‬ ‭ ‬‭‬ = ‭‬{‭ ‬‭|‬‭‬‭ ‬‭≥‬‭‬‭2‬} ‭ ‬ ‭of‬ ‭such‬ ‭that‬ ‭is‬ ‭greater‬ ‭than‬ ‭or‬ ‭equal‬ ‭to‬ ‭2.‬ ‭This‬ ‭can‬ ‭be‬ ‭shown‬ ‭graphically‬ ‭on‬ ‭the‬ ‭number‬ ‭line‬ ‭as‬ ‭ ‬ ‭ ‬ ‭follows:‬

‭© 2023 ACHIEVE ULTIMATE CREDIT-BY-EXAM GUIDE‬‭|‬‭COLLEGE MATH‬

‭3‬

‭It‬ ‭must‬ ‭be‬‭noted‬‭that‬‭in‬‭the‬‭above‬‭number‬‭line,‬‭there‬‭is‬‭a‬‭closed‬‭bracket‬‭[‬‭at‬‭2,‬‭which‬‭means‬‭that‬‭2‬‭is‬ ‭also‬‭included‬‭in‬‭the‬‭expression.‬‭In‬‭contrast,‬‭the‬‭expression‬ ‭is‬‭represented‬‭on‬‭the‬‭number‬ ‭ ‬ = {‭ ‬‭|‬‭ ‬ > ‭2‬} ‭line as follows:‬

‭When‬‭a‬‭parenthesis‬‭(‬‭is‬‭used‬‭on‬‭the‬‭number‬‭line,‬‭it‬‭means‬‭that‬‭all‬‭numbers‬‭greater‬‭than‬‭2,‬‭excluding‬‭2,‬ ‭are‬‭to‬‭be‬‭considered‬‭here.‬‭In‬‭other‬‭words,‬‭while‬‭using‬‭inequalities,‬‭we‬‭may‬‭make‬‭use‬‭of‬‭different‬‭types‬ ‭of‬ ‭brackets‬ ‭that‬ ‭have‬ ‭different‬ ‭meanings.‬ ‭For‬ ‭instance,‬ ‭means‬ ‭the‬ ‭set‬ ‭contains‬ ‭all‬‭the‬‭numbers‬ (‭ ‬, ‭ ‬) ‭between‬ ‭and‬ ‭,‬ ‭excluding‬ ‭and‬ ‭.‬ ‭On‬ ‭the‬ ‭contrary,‬ ‭means‬ ‭all‬ ‭numbers‬ ‭between‬ ‭and‬ ‭,‬ ‭ ‬ ‭ ‬ ‭ ‬ ‭ ‬ [‭ ‬, ‭‬‭ ‬] ‭ ‬ ‭ ‬ ‭including‬ ‭and‬ ‭.‬ ‭ ‬ ‭ ‬ ‭Similarly,‬ ‭means‬‭all‬‭numbers‬‭between‬ ‭and‬ ‭,‬‭inclusive‬‭of‬ ‭and‬‭exclusive‬‭of‬ ‭.‬‭This‬‭is‬‭known‬‭an‬ [‭ ‬, ‭‬‭ ‬) ‭ ‬ ‭ ‬ ‭ ‬ ‭ ‬ ‭interval notation. Let us understand this using a few examples:‬ ‭Set-Builder Notation‬ ‭Graphical Representation‬ ‭Interval Notation‬ {‭ ‬‭|‬‭‬‭ ‬‭‬ > ‭‬‭4‬} (‭4‬, ‭∞‬) {‭ ‬‭|‬‭‬‭ ‬‭‬ < ‭‬‭2‬} (− ‭∞‬, ‭2‬) { ‭ ‬‭| ‬‭ ‬‭ ‬‭ ‬‭≤ ‬‭ ‬‭1 ‬} (− ‭∞‬, ‭1‬] {‭ ‬‭|‬‭‬‭ ‬‭‬‭≥‬‭‬ − ‭3‬} [− ‭3‬, ‭∞‬) ‭C. Mathematical Translations of Equalities from Words‬ ‭An‬‭equation‬‭is‬‭used‬‭to‬‭show‬‭that‬‭two‬‭mathematical‬‭expressions‬‭are‬‭equal‬‭to‬‭each‬‭other.‬ ‭For‬‭instance,‬ ‭.‬ ‭This‬ ‭is‬ ‭as‬ ‭an‬ ‭equation‬ ‭since‬ ‭the‬‭expressions‬‭on‬‭both‬‭sides‬‭of‬‭the‬‭sentence‬‭are‬‭equal‬‭and‬ ‭2‬‭ ‬ + ‭5‬ = ‭9‬ ‭denoted by the equal to (=) sign. Some of the examples of equations are:‬ ‭3‬ + ‭5‬ = ‭8‬ ‭2 ‭5 ‭7 ‬ ‬‭ 0 * ‬‭– ‬‭ 1 ‭3 ‬ 0 ‬ = = ‬= ‭2 ‭8 8 ‭1 – 0 0 2 ‬ ‬ ‬ ‭In these examples, the expressions on either side of the equal sign are equal to each other.‬

‭© 2023 ACHIEVE ULTIMATE CREDIT-BY-EXAM GUIDE‬‭|‬‭COLLEGE MATH‬

‭4‬

‭Written‬‭sentences‬‭can‬‭be‬‭converted‬‭into‬‭mathematical‬‭expressions‬‭so‬‭that‬‭they‬‭can‬‭be‬‭solved‬‭to‬‭arrive‬ ‭at‬ ‭meaningful‬ ‭solutions.‬ ‭For‬ ‭instance,‬ ‭“a‬ ‭number‬ ‭is‬ ‭multiplied‬ ‭by‬ ‭10‬ ‭and‬ ‭then‬ ‭added‬ ‭to‬ ‭8‬‭to‬‭get‬‭48”.‬ ‭Assume the number is‬ ‭and the mathematical equation becomes:‬ ‭ ‬ ‭10‬‭ ‬ + ‭8‬ = ‭48‬ ‭It‬ ‭should‬‭be‬‭noted‬‭that‬‭the‬‭two‬‭sides‬‭of‬‭the‬‭equation‬‭should‬‭balance‬‭each‬‭other‬‭using‬‭the‬‭equal‬‭to‬‭(=)‬ ‭sign. Let us solve a few more examples to get a better understanding.‬

‭Word Problem‬

‭Algebraic Translation‬

( ‭2 ‬‭ ‬‭ ‭2‬+‬ ‭1 0 ‬) = ‭35‬ ‭2 ‭ ‬ ‬ ‭ ‬‭– ‬‭ ‬‭6 ‬‭ ‬‭– ‬‭ ‬‭5 ‬‭ ‬ = ‭ ‬‭3 ‬

‭Kathy‬‭asks‬‭her‬‭mother‬‭how‬‭old‬‭she‬‭is.‬‭Her‬‭mother‬‭replies,‬‭“If‬‭you‬ ‭double my age and add 10 to it, then divide by 2, you get 35.”‬

‭Marlin‬‭gets‬‭his‬‭monthly‬‭pocket‬‭money.‬‭He‬‭saves‬‭half‬‭of‬‭it,‬‭and‬‭then‬ ‭makes‬ ‭two‬ ‭purchases‬ ‭worth‬ ‭$6‬ ‭and‬ ‭$5.‬ ‭Finally‬ ‭when‬‭he‬‭reaches‬ ‭home, he is left with $3.‬

‭A‬ ‭bus‬ ‭starts‬ ‭leaves‬ ‭the‬ ‭station‬ ‭filled‬‭to‬‭capacity.‬‭At‬‭the‬‭first‬‭stop,‬ ‭half‬‭the‬‭passengers‬‭get‬‭off‬‭and‬‭10‬‭get‬‭on‬‭board.‬‭At‬‭the‬‭next‬‭station,‬ ‭12‬‭get‬‭off‬‭while‬‭15‬‭get‬‭on‬‭board.‬‭Now,‬‭the‬‭number‬‭of‬‭passengers‬‭in‬ ‭the bus is 28.‬

‭ ‬− ‭2 ‭ ‬ ‬ + ‭10‬ − ‭12‬ + ‭15‬ = ‭28‬

‭D. Mathematical Translations of Inequalities from Words‬ ‭Inequalities‬ ‭can‬ ‭also‬ ‭be‬ ‭translated‬ ‭from‬ ‭words‬‭into‬‭mathematical‬‭equations.‬‭For‬‭instance,‬‭we‬‭need‬‭to‬ ‭translate‬ ‭the‬ ‭sentence,‬ ‭“a‬ ‭number‬ ‭minus‬ ‭6‬ ‭is‬ ‭less‬ ‭than‬ ‭2”‬ ‭into‬ ‭an‬ ‭inequality.‬ ‭“A‬ ‭number”‬ ‭states‬ ‭the‬ ‭presence‬ ‭of‬ ‭an‬ ‭unknown‬ ‭variable.‬ ‭Let‬ ‭us‬ ‭denote‬ ‭that‬ ‭by‬ ‭.‬ ‭After‬‭subtracting‬‭6‬‭from‬ ‭,‬‭this‬‭expression‬ ‭ ‬ ‭ ‬ ‭should be less than (denoted by inequality sign <) 2. Now the expression becomes:‬ ‭ ‬‭–6‬ < ‭2‬ ‭Similarly,‬ ‭mathematical‬ ‭expressions‬ ‭can‬ ‭be‬ ‭formed‬ ‭using‬ ‭different‬‭inequality‬‭notations‬‭like‬‭more‬‭than‬ ‭(>), less than (<), at most (≤), at least (≥), etc., as shown below.‬

‭ ‬ + ‭5‬ < ‭15‬ ‭5‬‭ ‬‭≤25‬ ‭ ‬ − ‭5≥17‬ ‭ ‬> ‭65‬

‭The sum of 5 more than the number is no more than 15‬

‭Five boxes of cereal costs at most 25 dollars‬

‭The difference between a number and 5 is at least 17‬

‭Jenny’s height is greater than 65 inches‬

‭E. Solving Equations‬ ‭In‬‭order‬‭to‬‭solve‬‭the‬‭equations,‬‭it‬‭is‬‭important‬‭to‬‭move‬‭all‬‭variables‬‭to‬‭one‬‭side‬‭using‬‭inverse‬‭operations‬ ‭(addition ‬ ‭subtraction‬ ‭&‬ ‭multiplication division).‬ ‭It‬ ‭should‬ ‭be‬ ‭noted‬ ‭that‬ ‭applying‬ ‭inverse‬ ‭operations‬ ‭on‬ ‭both‬ ‭sides‬ ‭of‬‭an‬‭equation‬‭keeps‬‭the‬‭balance.‬‭For‬‭instance,‬‭the‬‭equation‬ ‭can‬‭be‬ ‭ ‬‭–3‬ = ‭7‬

‭© 2023 ACHIEVE ULTIMATE CREDIT-BY-EXAM GUIDE‬‭|‬‭COLLEGE MATH‬

‭5‬

‭Chapter 2:‬ ‭Financial Mathematics‬

‭Overview‬ ‭Money‬ ‭is‬ ‭an‬ ‭essential‬ ‭component‬‭of‬‭everyday‬‭life.‬‭Sometimes‬‭we‬‭work‬‭to‬‭earn‬‭money‬‭and‬‭sometimes‬ ‭money‬ ‭works‬ ‭for‬ ‭us,‬ ‭helping‬ ‭us‬ ‭earn‬ ‭more‬ ‭money.‬ ‭Financial‬ ‭mathematics‬ ‭deals‬ ‭with‬ ‭applies‬ ‭mathematics‬‭to‬‭real‬‭life‬‭situations.‬‭We‬‭all‬‭make‬‭purchases‬‭of‬‭physical‬‭as‬‭well‬‭as‬‭financial‬‭products‬‭and‬ ‭services‬‭and‬‭with‬‭the‬‭help‬‭of‬‭financial‬‭mathematics,‬‭we‬‭can‬‭become‬‭smart‬‭consumers.‬‭The‬‭motivation‬‭of‬ ‭this‬‭course‬‭is‬‭not‬‭just‬‭to‬‭excel‬‭in‬‭your‬‭educational‬‭career,‬‭but‬‭to‬‭equip‬‭you‬‭with‬‭the‬‭skills‬‭to‬‭understand‬ ‭the‬ ‭daily‬ ‭transactions‬ ‭happening‬ ‭around‬ ‭you.‬ ‭You‬ ‭will‬ ‭become‬ ‭an‬ ‭intelligent‬ ‭consumer‬ ‭and‬ ‭saver‬ ‭by‬ ‭learning even the basic concepts underlying financial mathematics.‬ ‭This‬ ‭chapter‬ ‭will‬ ‭cover‬ ‭important‬ ‭concepts‬ ‭like‬ ‭percentage,‬ ‭discounts,‬ ‭markups,‬ ‭taxes,‬ ‭changes‬ ‭in‬ ‭percentage,‬ ‭profits‬ ‭and‬ ‭losses.‬ ‭Further,‬ ‭the‬ ‭financial‬‭transactions‬‭taking‬‭place‬‭in‬‭the‬‭financial‬‭markets‬ ‭are‬ ‭also‬ ‭taught‬ ‭in‬ ‭this‬ ‭lesson,‬ ‭which‬ ‭consists‬ ‭of‬ ‭simple‬ ‭interest,‬ ‭compound‬ ‭interest,‬ ‭effective‬ ‭rate‬ ‭of‬ ‭interest, continuous compounding, effective annual yield, and present and future values.‬ ‭Objectives‬

‭By the end of the chapter, you will be able to understand and apply the concepts of:‬

‭●‬ ‭Percentages and their usages‬ ‭●‬ ‭Changes in percentages‬ ‭●‬ ‭Different interest rates‬ ‭●‬ ‭Compounding techniques‬ ‭●‬ ‭Present and future value‬

‭A. Percent‬ ‭We‬ ‭are‬ ‭familiar‬ ‭with‬ ‭the‬ ‭word‬ ‭‘percentage’‬‭and‬‭often‬‭use‬‭it‬‭to‬‭describe‬‭interest‬‭rates,‬‭growth‬‭in‬‭sales,‬ ‭exam‬‭scores,‬‭etc.‬‭For‬‭example,‬‭if‬‭a‬‭student‬‭scored‬‭85%‬‭on‬‭the‬‭CLEP‬‭college‬‭mathematics‬‭examination,‬‭it‬ ‭would mean they got 85 questions correct out of 100:‬ ‭1 ‭8 0 5 0 ‬ ‬ ‭%‬ ‭But‬‭what‬‭does‬‭percent‬‭or‬‭percentage‬‭mean?‬‭Percent‬‭is‬‭generally‬‭used‬‭to‬‭describe‬‭any‬‭value‬‭‘out‬‭of‬‭100’,‬ ‭which‬ ‭means‬ ‭‘divide‬ ‭by‬‭100’.‬‭The‬‭denominator,‬‭however,‬‭does‬‭not‬‭always‬‭default‬‭to‬‭100.‬‭In‬‭that‬‭case,‬ ‭make‬ ‭the‬ ‭denominator‬‭100‬‭by‬‭multiplying‬‭the‬‭factor‬‭by‬‭a‬‭scaler.‬‭For‬‭example,‬‭suppose‬‭Randall‬‭scored‬ ‭15 out of 20, then the fraction becomes:‬ ‭1 ‭2 5 0 ‬ ‬

‭© 2023 ACHIEVE ULTIMATE CREDIT-BY-EXAM GUIDE‬‭|‬‭COLLEGE MATH‬

‭26‬

‭Now, multiply both numerator and denominator by 5 so that the denominator becomes 100.‬ ‭1 ‭2 5 0 ‬ ‬ * ‭5 ‭5 ‬ ‬ = ‭1 ‭7 0 5 0 ‬ ‬ ‭Let‬‭us‬‭consider‬‭another‬‭case,‬‭where‬‭you‬‭have‬‭scored‬‭65‬‭out‬‭of‬‭75.‬‭Now‬‭in‬‭this‬‭case,‬‭multiply‬‭and‬‭divide‬ ‭the fraction by 100 and substitute the 100 in denominator as % sign and simplify the same:‬ ‭6 ‭7 5 5 ‬ ‬ * ‭1‭1 00 00 ‬‬ = ‭6 ‭7 5 5 ‬ ‬ * ‭100‬‭‬‭%‬ = ‭86‬. ‭67%‬ ‭Sometimes‬‭we‬‭need‬‭to‬‭find‬‭the‬‭percentage‬‭of‬‭a‬‭particular‬‭value--for‬‭example,‬‭calculating‬‭a‬‭10%‬‭tip‬‭on‬‭a‬ ‭restaurant check of $460. To do this, find 10 percent of $460. Mathematically,‬ ‭1 ‭1 0 0 0 ‬ ‬ * ‭460‬ = ‭$46‬ ‭B. Discounts, Markups, and Taxation‬ ‭We‬ ‭all‬ ‭are‬ ‭familiar‬ ‭with‬ ‭the‬ ‭terms‬ ‭like‬ ‭‘discounts,‬ ‭markups,‬ ‭and‬ ‭taxation.’‬ ‭Calculating‬ ‭these‬ ‭amounts‬ ‭makes‬‭use‬‭of‬‭percentage‬‭concepts‬‭in‬‭the‬‭previous‬‭section.‬‭For‬‭example,‬‭you‬‭go‬‭to‬‭a‬‭grocery‬‭store‬‭where‬ ‭you‬ ‭see‬ ‭an‬‭offer‬‭that‬‭if‬‭you‬‭spend‬‭over‬‭$500,‬‭you‬‭get‬‭a‬‭5%‬‭discount.‬‭If,‬‭for‬‭example,‬‭you‬‭spend‬‭$570,‬ ‭then you can find the discount amount by finding 5% OF the total, that is:‬ ‭1 ‭5 0 ‬ 0‬ * ‭570‬ = ‭$28‬. ‭5‬ ‭So, you pay 570 less 28.5 = $541.5‬ ‭Alternatively,‬‭we‬‭know‬‭that‬‭100%‬‭of‬‭a‬‭value‬‭is‬‭equal‬‭to‬‭570.‬‭Since‬‭you‬‭get‬‭a‬‭discount‬‭of‬‭5%,‬‭you‬‭end‬‭up‬ ‭paying (100% - 5%) of the purchase price. That is:‬ ‭1 ‭9 0 5 0 ‬ ‬ * ‭570‬ = ‭$571‬. ‭5‬ ‭Just‬ ‭remember‬ ‭that‬ ‭a‬ ‭decrease‬ ‭in‬ ‭the‬ ‭price‬ ‭of‬ ‭an‬ ‭item‬ ‭(as‬ ‭compared‬ ‭to‬ ‭its‬ ‭list‬ ‭price)‬ ‭is‬ ‭termed‬ ‭as‬ ‭discount.‬ ‭Markup‬‭is‬‭when‬‭the‬‭price‬‭of‬‭an‬‭item‬‭is‬‭increased‬‭from‬‭its‬‭base‬‭price.‬‭For‬‭instance,‬‭a‬‭retailer‬‭purchases‬ ‭items‬‭from‬‭a‬‭wholesaler‬‭or‬‭manufacturer‬‭at‬‭wholesale‬‭price‬‭and‬‭then‬‭sells‬‭the‬‭same‬‭products‬‭at‬‭a‬‭higher‬ ‭price.‬ ‭The‬ ‭difference‬ ‭between‬ ‭the‬ ‭two‬ ‭prices‬ ‭is‬ ‭the‬ ‭‘markup.’‬ ‭For‬ ‭instance,‬ ‭an‬ ‭apparel‬ ‭outlet‬‭sources‬ ‭mens‬ ‭denims‬ ‭from‬ ‭the‬ ‭wholesaler‬ ‭at‬ ‭$50,‬ ‭and‬ ‭then‬ ‭adds‬‭their‬‭markup‬‭of‬‭60%‬‭before‬‭selling‬‭it‬‭to‬‭the‬ ‭customers. What is the retail price?‬ ‭Now,‬ ‭we‬ ‭can‬ ‭calculate‬ ‭the‬ ‭same‬ ‭in‬ ‭two‬ ‭ways.‬ ‭First,‬ ‭calculate‬ ‭the‬ ‭amount‬ ‭of‬ ‭markup‬ ‭and‬ ‭add‬ ‭to‬ ‭the‬ ‭purchase price. That is:‬ ‭ ‬‭‬‭ ‬ = ‭‬ ‭1 ‭6 0 0 0 ‬ ‬ * ‭50‬ = ‭$30‬ ‭Retail price = purchase price + mark up = 50 + 30 = $80‬ ‭= 75%‬

‭© 2023 ACHIEVE ULTIMATE CREDIT-BY-EXAM GUIDE‬‭|‬‭COLLEGE MATH‬

‭27‬

‭Chapter 3:‬ ‭Geometry‬

‭Overview‬ ‭Geometry‬‭is‬‭an‬‭essential‬‭part‬‭of‬‭mathematics,‬‭as‬‭it‬‭provides‬‭geometric‬‭reasoning‬‭to‬‭problem‬‭solving.‬‭We‬ ‭all‬‭deal‬‭with‬‭different‬‭geometric‬‭shapes‬‭in‬‭our‬‭daily‬‭lives,‬‭like‬‭circles,‬‭triangles,‬‭rectangles,‬‭squares,‬‭etc.‬ ‭For‬‭instance,‬‭you‬‭go‬‭for‬‭daily‬‭walk‬‭in‬‭a‬‭rectangular‬‭park‬‭and‬‭you‬‭need‬‭to‬‭see‬‭how‬‭many‬‭miles‬‭you‬‭walk‬ ‭daily,‬ ‭so‬ ‭you‬ ‭can‬ ‭find‬ ‭out‬ ‭by‬ ‭learning‬ ‭about‬ ‭the‬ ‭perimeter‬‭of‬‭that‬‭rectangle.‬‭Similarly,‬‭you‬‭want‬‭to‬‭get‬ ‭your‬ ‭window‬‭painted‬‭which‬‭looks‬‭like‬‭a‬‭semi-circle‬‭on‬‭the‬‭top‬‭of‬‭a‬‭square,‬‭and‬‭the‬‭painter‬‭asks‬‭you‬‭to‬ ‭pay‬‭him‬‭$2.50‬‭per‬‭square‬‭meter‬‭of‬‭that‬‭window.‬‭So‬‭here‬‭you‬‭need‬‭to‬‭be‬‭aware‬‭about‬‭the‬‭area‬‭of‬‭triangle‬ ‭and‬ ‭semi-circle.‬ ‭Similarly,‬ ‭there‬ ‭are‬ ‭many‬ ‭more‬ ‭instances‬‭where‬‭you‬‭make‬‭use‬‭of‬‭geometrical‬‭shapes‬ ‭around‬ ‭you.‬ ‭The‬ ‭course‬‭in‬‭geometry‬‭will‬‭provide‬‭you‬‭with‬‭basic‬‭skills‬‭in‬‭lines,‬‭triangles,‬‭quadrilaterals,‬ ‭and circles that will hone your problem-solving in dealing with different shapes.‬ ‭In‬ ‭this‬ ‭chapter,‬ ‭you‬ ‭will‬ ‭learn‬ ‭about‬‭the‬‭concepts,‬‭classification,‬‭properties‬‭and‬‭theorems‬‭of‬‭triangles,‬ ‭different‬‭quadrilaterals‬‭and‬‭how‬‭they‬‭differ‬‭from‬‭each‬‭other,‬‭parallel‬‭and‬‭perpendicular‬‭lines‬‭in‬‭a‬‭plane‬

‭and circles.‬ ‭Objectives‬

‭By the end of the chapter, you will be able to learn the concepts and their application in:‬

‭●‬ ‭Triangles and their types‬ ‭●‬ ‭Area and perimeter of triangles‬ ‭●‬ ‭Quadrilaterals- classification, area, and perimeter‬ ‭●‬ ‭Parallel and perpendicular lines‬ ‭●‬ ‭Circles and its properties, circumference, and area‬ ‭●‬ ‭Theorems of circles to measure different angles‬ ‭A. Triangles‬

‭Triangles‬ ‭can‬ ‭be‬ ‭defined‬ ‭as‬ ‭any‬ ‭geometric‬ ‭figure‬ ‭which‬ ‭has‬ ‭three‬ ‭angles‬ ‭and‬ ‭three‬ ‭sides.‬ ‭Before‬ ‭we‬ ‭move‬ ‭to‬ ‭understand‬ ‭the‬ ‭properties‬ ‭and‬ ‭application‬ ‭of‬ ‭triangles,‬ ‭let‬ ‭us‬ ‭understand‬ ‭different‬ ‭types‬ ‭of‬ ‭angles.‬ ‭Angles‬ ‭can‬‭be‬‭classified‬‭as‬‭acute‬‭angles‬‭(that‬‭measures‬‭less‬‭than‬‭90‬ ‭0‬ ‭),‬‭right‬‭angles‬‭(measures‬ ‭exactly‬‭90‬ ‭0‬ ‭),‬‭obtuse‬‭angles‬‭(measures‬‭more‬‭than‬‭90‬ ‭0‬ ‭),‬‭and‬‭straight‬‭angle‬‭(measures‬‭exactly‬‭180‬ ‭0‬ ‭).‬‭The‬ ‭shapes of these angles look like the ones given here:‬

‭© 2023 ACHIEVE ULTIMATE CREDIT-BY-EXAM GUIDE‬‭|‬‭COLLEGE MATH‬

‭38‬

‭Based‬ ‭on‬ ‭these‬ ‭properties‬ ‭of‬ ‭angles,‬ ‭triangles‬ ‭are‬ ‭also‬ ‭classified‬ ‭as‬ ‭acute‬ ‭triangle‬ ‭(wherein‬ ‭all‬ ‭three‬ ‭angles‬ ‭of‬ ‭the‬ ‭triangle‬ ‭are‬ ‭acute),‬ ‭right‬ ‭triangle‬ ‭(one‬ ‭angle‬ ‭of‬ ‭the‬ ‭triangle‬ ‭is‬ ‭a‬‭right‬‭angle),‬‭and‬‭obtuse‬ ‭triangle‬ ‭(one‬ ‭angle‬ ‭of‬ ‭the‬‭triangle‬‭is‬‭an‬‭obtuse‬‭angle).‬‭It‬‭should‬‭also‬‭be‬‭noted‬‭that‬‭the‬‭sum‬‭total‬‭of‬‭all‬ ‭three‬‭angle‬‭of‬‭the‬‭triangles‬‭should‬‭always‬‭be‬‭equal‬‭to‬‭180‬ ‭0‬ ‭.‬‭The‬‭different‬‭types‬‭of‬‭triangles‬‭categorized‬ ‭on angles are given as follows:‬

‭Triangles‬ ‭can‬ ‭also‬ ‭be‬ ‭categorized‬ ‭on‬ ‭the‬ ‭basis‬ ‭of‬ ‭their‬ ‭sides,‬ ‭and‬ ‭are‬ ‭termed‬‭as‬‭scalene‬‭(none‬‭of‬‭the‬ ‭sides‬ ‭of‬ ‭the‬ ‭triangle‬ ‭are‬ ‭congruent‬ ‭or‬ ‭same),‬ ‭isosceles‬ ‭(two‬ ‭sides‬ ‭of‬ ‭the‬ ‭triangle‬ ‭are‬ ‭congruent),‬‭and‬ ‭equilateral‬ ‭(when‬ ‭all‬‭three‬‭sides‬‭of‬‭the‬‭triangle‬‭are‬‭congruent).‬‭The‬‭classification‬‭of‬‭triangles‬‭based‬‭on‬ ‭sides is shown here:‬

‭Triangle‬‭inequality‬‭theorem‬ ‭states‬‭that‬‭the‬‭sum‬‭of‬‭two‬‭sides‬‭of‬‭any‬‭triangle‬‭will‬‭always‬‭be‬‭greater‬‭than‬ ‭the‬ ‭third‬ ‭side.‬ ‭For‬ ‭instance,‬ ‭a‬ ‭triangle‬ ‭cannot‬ ‭be‬ ‭formed‬ ‭if‬ ‭its‬ ‭sides‬ ‭are‬ ‭measured‬ ‭as‬ ‭5cm,‬ ‭7cm‬ ‭and‬ ‭13cm, since adding two sides: 5+7 is not greater than the third side, that is, 13cm.‬ ‭Area of a triangle:‬ ‭The area of the triangle can be‬‭found by using the following formula:‬ ‭ ‬‭‬‭ ‬‭‬‭ ‬ = ‭1 ‭2 ‬ ‬ * ‭ ‬ * ‭ℎ ℎ ‬= ‭ ‭2 ℎ ‬ ‬ ‭The‬ ‭perimeter‬‭of‬‭the‬‭triangle‬ ‭can‬‭be‬‭found‬‭by‬‭adding‬‭the‬‭measure‬‭of‬‭all‬‭three‬‭sides‬‭of‬‭a‬‭triangle,‬‭that‬‭is‬ ‭P = a + b + c‬ ‭Pythagorean‬ ‭Theorem:‬ ‭This‬‭theorem‬‭is‬‭applicable‬‭only‬‭to‬‭right‬‭angle‬‭triangle.‬‭As‬‭per‬‭the‬‭Pythagorean‬ ‭Theorem,‬‭the‬‭square‬‭of‬‭the‬‭hypotenuse‬‭of‬‭the‬‭triangle‬‭is‬‭equal‬‭to‬‭the‬‭square‬‭of‬‭the‬‭other‬‭two‬‭sides‬‭of‬‭the‬ ‭triangle.‬ ‭The‬ ‭side‬‭opposite‬‭to‬‭the‬‭right‬‭angle‬‭of‬‭the‬‭right‬‭angle‬‭triangle‬‭is‬‭known‬‭as‬‭the‬‭hypotenuse.‬‭In‬ ‭the given triangle,‬

‭© 2023 ACHIEVE ULTIMATE CREDIT-BY-EXAM GUIDE‬‭|‬‭COLLEGE MATH‬

‭39‬

‭Chapter 4:‬ ‭Counting and Probability‬

‭Overview‬

‭We‬ ‭make‬ ‭use‬ ‭of‬ ‭counting‬ ‭and‬ ‭probability‬ ‭in‬ ‭our‬ ‭everyday‬ ‭life‬ ‭very‬ ‭often,‬ ‭like‬ ‭when‬ ‭we‬ ‭say‬ ‭there‬‭is‬‭a‬ ‭likelihood‬ ‭of‬ ‭rain‬ ‭tomorrow.‬ ‭Similarly,‬‭we‬‭often‬‭make‬‭use‬‭of‬‭words‬‭like‬‭likely,‬‭probably,‬‭chance,‬‭etc.‬‭In‬ ‭such‬ ‭cases,‬ ‭we‬ ‭are‬ ‭not‬ ‭certain‬ ‭about‬ ‭the‬ ‭future‬ ‭happening‬ ‭but‬ ‭we‬ ‭are‬ ‭certain‬ ‭that‬ ‭it‬ ‭will‬ ‭happen.‬ ‭Counting‬‭and‬‭probability‬‭help‬‭equip‬‭you‬‭with‬‭the‬‭basic‬‭understanding‬‭of‬‭determining‬‭chances‬‭when‬‭we‬ ‭deal‬ ‭with‬‭different‬‭experiments,‬‭like‬‭the‬‭lottery,‬‭winning‬‭at‬‭casinos,‬‭playing‬‭cards,‬‭and‬‭other‬‭forecasts.‬ ‭Finally, it facilitates healthy decision making in the light of uncertain future in different disciplines.‬ ‭In‬ ‭this‬ ‭chapter,‬ ‭you‬ ‭will‬ ‭learn‬ ‭the‬ ‭concepts‬ ‭and‬ ‭application‬ ‭of‬ ‭different‬ ‭counting‬ ‭techniques‬ ‭and‬ ‭probability‬‭situations.‬‭The‬‭chapter‬‭will‬‭majorly‬‭cover‬‭the‬‭fundamental‬‭counting‬‭principle,‬‭permutations,‬ ‭combinations,‬ ‭and‬ ‭theories‬ ‭of‬ ‭probability.‬ ‭The‬ ‭theories‬ ‭and‬ ‭techniques‬ ‭presented‬ ‭in‬ ‭this‬ ‭chapter‬ ‭will‬ ‭also be applied in real life situations by way of different arbitrary examples.‬ ‭Objectives‬

‭By the end of this chapter, you will learn, solve and gain expertise in:‬

‭●‬ ‭Counting technique and rule‬ ‭●‬ ‭Permutation and combination‬ ‭●‬ ‭Probability with mutually exclusive and independent events‬ ‭●‬ ‭Union and intersection of probabilities‬ ‭●‬ ‭Expected value of payoffs‬ ‭●‬ ‭Conditional probability‬ ‭A. Counting‬

‭Mathematics‬‭involves‬‭the‬‭use‬‭of‬‭counting‬‭and‬‭we‬‭make‬‭use‬‭of‬‭different‬‭counting‬‭throughout‬‭our‬‭day.‬‭For‬ ‭instance,‬‭you‬‭go‬‭to‬‭Cocoberry‬‭Frozen‬‭Yogurt,‬‭where‬‭you‬‭can‬‭select‬‭a‬‭flavor‬‭and‬‭toppings‬‭for‬‭yourself.‬‭The‬ ‭vendor‬ ‭asks‬ ‭you‬ ‭to‬ ‭choose‬ ‭between‬ ‭green‬ ‭apple,‬ ‭mango,‬ ‭strawberry,‬ ‭blackberry,‬ ‭blueberry,‬ ‭or‬ ‭black‬ ‭currant‬‭as‬‭your‬‭base‬‭flavor.‬‭Not‬‭just‬‭this,‬‭now‬‭you‬‭have‬‭to‬‭choose‬‭one‬‭topping‬‭among‬‭the‬‭12‬‭options‬‭of‬ ‭fruits,‬ ‭nuts,‬ ‭and‬ ‭syrups;‬ ‭in‬ ‭this‬ ‭example‬ ‭counting‬ ‭can‬ ‭help‬ ‭to‬ ‭determine‬ ‭the‬ ‭total‬ ‭number‬ ‭of‬ ‭ways‬ ‭in‬ ‭which you can select your flavor.‬ ‭Similarly,‬‭we‬‭make‬‭use‬‭of‬‭counting‬‭in‬‭every‬‭sphere‬‭of‬‭life.‬‭It‬‭is‬‭easy‬‭to‬‭determine‬‭in‬‭simple‬‭cases‬‭where‬ ‭the‬ ‭options‬ ‭available‬ ‭are‬ ‭less,‬ ‭for‬ ‭instance,‬ ‭travelling‬ ‭between‬ ‭two‬ ‭cities‬ ‭involves‬ ‭three‬ ‭ways.‬ ‭The‬ ‭problem arises when the number of choices increases, like the case of Cocoberry Frozen Yogurt.‬ ‭Let‬ ‭use‬ ‭learn‬ ‭some‬ ‭simple‬ ‭rules‬ ‭of‬ ‭counting‬ ‭that‬ ‭helps‬ ‭to‬ ‭solve‬ ‭such‬‭problems.‬‭Before‬‭moving‬‭to‬‭the‬ ‭rules, let us solve one simple problem of counting.‬

‭© 2023 ACHIEVE ULTIMATE CREDIT-BY-EXAM GUIDE‬‭|‬‭COLLEGE MATH‬

‭53‬

‭Suppose‬ ‭Emily,‬ ‭who‬ ‭resides‬ ‭in‬‭city‬‭A,‬‭wishes‬‭to‬‭go‬‭to‬‭city‬‭C‬‭via‬‭city‬‭B.‬‭It‬‭is‬‭known‬‭that‬‭there‬‭are‬‭three‬ ‭different‬‭routes‬‭between‬‭city‬‭A‬‭and‬‭B,‬‭and‬‭then‬‭there‬‭are‬‭two‬‭different‬‭routes‬‭between‬‭city‬‭B‬‭and‬‭C.‬‭Now‬ ‭we‬ ‭have‬ ‭to‬ ‭calculate‬ ‭how‬ ‭many‬ ‭options‬ ‭does‬ ‭Emily‬ ‭have?‬ ‭Let‬ ‭us‬ ‭understand‬ ‭this‬ ‭by‬ ‭drawing‬ ‭a‬ ‭tree‬ ‭diagram. Tree diagram refers to the graphical representation of all possible outcomes.‬

‭In‬‭the‬‭above‬‭case,‬‭Emily‬‭has‬‭a‬‭total‬‭of‬‭six‬‭options‬‭to‬‭travel‬‭from‬‭city‬‭A‬‭and‬‭City‬‭C‬‭via‬‭city‬‭B,‬‭that‬‭are‬‭ad,‬ ‭ae,‬‭bf,‬‭bg,‬‭ch,‬‭and‬‭ci.‬‭Hence,‬‭there‬‭are‬‭a‬‭total‬‭of‬‭six‬‭options.‬‭It‬‭will‬‭be‬‭tough‬‭to‬‭count‬‭the‬‭total‬‭possibilities‬ ‭if the sample space is much higher. Sample space refers to the set of all possible outcomes.‬ ‭B. Fundamental Counting Principle‬ ‭If‬‭one‬‭event‬‭occurs‬‭in‬‭m‬‭ways,‬‭and‬‭another‬‭event‬‭occurs‬‭in‬‭n‬‭ways‬‭after‬‭the‬‭occurrence‬‭of‬‭m,‬‭then‬‭the‬ ‭total‬ ‭number‬ ‭of‬ ‭ways‬ ‭in‬ ‭which‬ ‭the‬ ‭two‬ ‭events‬ ‭can‬ ‭occur‬ ‭is‬ ‭calculated‬ ‭as‬ ‭m‬ ‭X‬ ‭n‬ ‭ways.‬ ‭In‬ ‭the‬ ‭above‬ ‭example,‬‭Emily‬‭can‬‭travel‬‭between‬‭city‬‭A‬‭and‬‭city‬‭B‬‭in‬‭three‬‭possible‬‭ways,‬‭and‬‭the‬‭number‬‭of‬‭ways‬‭in‬ ‭which‬ ‭between‬ ‭city‬ ‭B‬ ‭and‬ ‭C‬ ‭is‬‭two.‬‭Applying‬‭the‬‭fundamental‬‭counting‬‭principle,‬‭the‬‭total‬‭numbers‬‭of‬ ‭ways in which Emily can travel are 3 * 2 = 6 ways.‬ ‭Let‬ ‭us‬ ‭take‬ ‭a‬ ‭few‬ ‭more‬ ‭examples‬ ‭to‬ ‭gain‬ ‭expertise‬ ‭in‬ ‭the‬ ‭concept.‬ ‭Remember‬ ‭the‬ ‭Cocoberry‬ ‭Frozen‬ ‭Yogurt‬‭offering‬‭the‬‭choice‬‭of‬‭6‬‭base‬‭flavors‬‭of‬‭yogurt‬‭and‬‭12‬‭options‬‭of‬‭toppings?‬‭We‬‭can‬‭calculate‬‭the‬ ‭total‬‭number‬‭of‬‭possibilities‬‭of‬‭different‬‭yogurts‬‭from‬‭the‬‭store‬‭using‬‭the‬‭counting‬‭principle.‬‭In‬‭this‬‭case,‬ ‭m‬ ‭=‬ ‭6‬ ‭and‬ ‭n‬ ‭=‬ ‭12.‬ ‭Thus,‬ ‭we‬ ‭can‬ ‭say‬ ‭that‬ ‭there‬ ‭are‬ ‭6*12‬ ‭=‬ ‭72‬ ‭ways‬ ‭of‬ ‭selecting‬‭the‬‭frozen‬‭yogurt‬‭at‬ ‭Cocoberry.‬ ‭Now,‬‭let‬‭us‬‭consider‬‭an‬‭example‬‭with‬‭a‬‭bigger‬‭sample‬‭space.‬‭In‬‭a‬‭country,‬‭the‬‭automobiles‬‭bear‬‭license‬ ‭plates‬ ‭with‬ ‭a‬ ‭combination‬ ‭of‬ ‭different‬ ‭letters‬ ‭and‬ ‭digits,‬ ‭such‬ ‭that‬ ‭the‬ ‭initial‬ ‭2‬ ‭positions‬ ‭are‬ ‭filled‬ ‭by‬ ‭letters‬ ‭and‬ ‭then‬ ‭the‬ ‭last‬ ‭three‬ ‭positions‬ ‭are‬ ‭taken‬ ‭by‬ ‭single‬ ‭digits.‬ ‭Now,‬ ‭what‬ ‭is‬ ‭the‬ ‭total‬ ‭number‬ ‭of‬ ‭possibilities of different license plates be made out of this?‬ ‭We‬‭know‬‭that,‬‭there‬‭are‬‭26‬‭letters‬‭(A‬‭to‬‭Z)‬‭and‬‭a‬‭total‬‭of‬‭10‬‭digits‬‭(from‬‭0‬‭to‬‭9).‬‭The‬‭number‬‭of‬‭ways‬‭in‬ ‭which‬ ‭first‬ ‭position‬ ‭of‬ ‭the‬ ‭license‬‭plate‬‭can‬‭be‬‭filled‬‭is‬‭26,‬‭the‬‭second‬‭position‬‭can‬‭also‬‭be‬‭filled‬‭in‬‭26‬ ‭ways,‬‭the‬‭third‬‭in‬‭10,‬‭the‬‭fourth‬‭in‬‭10,‬‭and‬‭the‬‭fifth‬‭position‬‭in‬‭10‬‭ways.‬‭Hence,‬‭the‬‭total‬‭number‬‭of‬‭ways‬ ‭the license plate can be made is:‬

‭© 2023 ACHIEVE ULTIMATE CREDIT-BY-EXAM GUIDE‬‭|‬‭COLLEGE MATH‬

‭54‬

End of Preview

For full access to the study guide, including detailed explanations and comprehensive review sections, please visit our website.

Achieve

© All Rights Reserved

Made with FlippingBook - Online Brochure Maker