Calculus I · Limits and Continuity · hub

Limits and Continuity Course Overview

Study limits and continuity from the beginning with a sequential Calculus I textbook, guided examples, quizzes, reviews, and practice exams.

Core textbook pathChoose the next lesson from the ordered unit map.

Core textbook

The complete textbook path

Follow the core path from the first neighborhood idea to formal epsilon-delta reasoning. Each section mixes explanation, guided examples, short checks, and deliberate review.

0103

Start here: orientation

Meet the purpose, prerequisite skills, and notation of the unit before solving a limit.

  1. 01Limits and Continuity Course OverviewOverview
  2. 02Calculus Limits Prerequisite DiagnosticDiagnostic
  3. 03Limit Notation GuideReference
0410

Section 1: What a limit means

Build the neighborhood idea with motion, tables, holes, one-sided behavior, and graphs.

  1. 04Why Limits Matter in CalculusLesson
  2. 05What a Limit MeansLesson
  3. 06Limits at Holes and Undefined PointsLesson
  4. 07Function Value vs. LimitLesson
  5. 08One-Sided Limits From the Left and RightLesson
  6. 09When a Limit Does Not ExistLesson
  7. 10How to Read Limits From a GraphLesson
1118

Section 2: Finite limits and algebra

Turn indeterminate forms into solvable expressions using substitution, limit laws, factoring, conjugates, and piecewise reasoning.

  1. 11Direct Substitution for LimitsLesson
  2. 12Limit Laws and How to Use ThemLesson
  3. 13What 0/0 Means in a LimitLesson
  4. 14Evaluating Limits by FactoringLesson
  5. 15Evaluating Radical Limits With ConjugatesLesson
  6. 16Limits With Complex FractionsLesson
  7. 17Limits With Absolute Values and Piecewise FunctionsLesson
  8. 18Finite Limit Decision TreeReference
1925

Section 3: Trigonometric limits

Use squeezing, the fundamental sine limit, identities, and scaling to make trigonometric behavior predictable.

  1. 19The Squeeze TheoremLesson
  2. 20Why sin(x)/x Approaches 1Lesson
  3. 21Geometric Proof of the sin(x)/x LimitLesson
  4. 22Scaled Sine and Tangent LimitsLesson
  5. 23Limits of Ratios of Sine FunctionsLesson
  6. 24Cosine Limits and Trigonometric IdentitiesLesson
  7. 25Trigonometric Limit Decision GuideReference
2632

Section 4: Infinite behavior

Read vertical, horizontal, and slant asymptotes through sign analysis and dominant-term reasoning.

  1. 26Infinite Limits ExplainedLesson
  2. 27Vertical Asymptotes and One-Sided Sign AnalysisLesson
  3. 28Limits at Infinity and Horizontal AsymptotesLesson
  4. 29Polynomial and Slant AsymptotesLesson
  5. 30Radical Limits at InfinityLesson
  6. 31Infinity Minus Infinity LimitsLesson
  7. 32Complete Rational Function Asymptote AnalysisLesson
3341

Section 5: Continuity

Connect limits to function values, classify discontinuities, repair piecewise definitions, and use the Intermediate Value Theorem.

  1. 33Continuity at a PointLesson
  2. 34Continuity on Intervals and at EndpointsLesson
  3. 35Which Functions Are Continuous?Reference
  4. 36Types of DiscontinuityLesson
  5. 37How to Repair a Removable DiscontinuityLesson
  6. 38Choosing Parameters for Piecewise ContinuityLesson
  7. 39Two-Parameter Continuity ProblemsLesson
  8. 40Intermediate Value TheoremLesson
  9. 41Bisection Method After the IVTLesson
4246

Section 6: Formal limits

Translate the intuitive neighborhood picture into epsilon-delta language, constructive proofs, graph windows, and counterexamples.

  1. 42Epsilon-Delta Definition: An IntroductionLesson
  2. 43Epsilon-Delta Proofs for Linear FunctionsLesson
  3. 44Epsilon-Delta Proofs for Quadratic FunctionsLesson
  4. 45Reading Epsilon and Delta From a GraphLesson
  5. 46How to Disprove a Claimed LimitLesson
4747

Section 7: Synthesis

Bring the unit together by choosing methods, explaining decisions, and correcting weak spots before an exam.

  1. 47Limits and Continuity Unit ReviewReview

Practice around the path

Reviews, quizzes, references, and exams

Use these between sections, after a confusing lesson, or as a mixed rehearsal before an exam. They support the sequence without interrupting it.

ReviewLimit Meaning ReviewReview Limit Meaning Review with a concise concept summary, common errors, and links to targeted practice.Concept quizLimit Meaning Concept QuizTest Limit Meaning Concept Quiz with short answer checks, hints, worked feedback, and links back to the exact lessons you need.Practice setLimit Meaning Practice ProblemsPractice Limit Meaning Practice Problems with warm-up, homework-level, reasoning, and exam-style problems plus answer support.ReviewFinite Limits ReviewReview Finite Limits Review with a concise concept summary, common errors, and links to targeted practice.Concept quizFinite Limits Concept QuizTest Finite Limits Concept Quiz with short answer checks, hints, worked feedback, and links back to the exact lessons you need.Practice setFinite Limit Practice ProblemsPractice Finite Limit Practice Problems with warm-up, homework-level, reasoning, and exam-style problems plus answer support.ReviewSqueeze and Trigonometric Limits ReviewReview Squeeze and Trigonometric Limits Review with a concise concept summary, common errors, and links to targeted practice.Concept quizTrigonometric Limits Concept QuizTest Trigonometric Limits Concept Quiz with short answer checks, hints, worked feedback, and links back to the exact lessons you need.Practice setTrigonometric Limit Practice ProblemsPractice Trigonometric Limit Practice Problems with warm-up, homework-level, reasoning, and exam-style problems plus answer support.ReviewInfinite Limits and Asymptotes ReviewReview Infinite Limits and Asymptotes Review with a concise concept summary, common errors, and links to targeted practice.Concept quizInfinite Limits Concept QuizTest Infinite Limits Concept Quiz with short answer checks, hints, worked feedback, and links back to the exact lessons you need.Practice setInfinite Limits and Asymptote PracticePractice Infinite Limits and Asymptote Practice with warm-up, homework-level, reasoning, and exam-style problems plus answer support.ReviewContinuity and IVT ReviewReview Continuity and IVT Review with a concise concept summary, common errors, and links to targeted practice.Concept quizContinuity Concept QuizTest Continuity Concept Quiz with short answer checks, hints, worked feedback, and links back to the exact lessons you need.Practice setContinuity and IVT Practice ProblemsPractice Continuity and IVT Practice Problems with warm-up, homework-level, reasoning, and exam-style problems plus answer support.ExtensionFormal Definition of an Infinite LimitGo beyond the standard unit with Formal Definition of an Infinite Limit, including formal definitions, worked reasoning, and optional proof practice.ReviewEpsilon-Delta ReviewReview Epsilon-Delta Review with a concise concept summary, common errors, and links to targeted practice.Concept quizEpsilon-Delta Concept QuizTest Epsilon-Delta Concept Quiz with short answer checks, hints, worked feedback, and links back to the exact lessons you need.Practice setEpsilon-Delta Practice ProblemsPractice Epsilon-Delta Practice Problems with warm-up, homework-level, reasoning, and exam-style problems plus answer support.ReviewCommon Limits Exam ErrorsReview Common Limits Exam Errors with a concise concept summary, common errors, and links to targeted practice.Study guideHow to Correct a Calculus Practice TestUse How to Correct a Calculus Practice Test to turn missed calculus questions into a concrete study plan instead of merely rereading solutions.Practice setCumulative Limits and Continuity PracticePractice Cumulative Limits and Continuity Practice with warm-up, homework-level, reasoning, and exam-style problems plus answer support.Practice examLimits and Continuity Practice Exam ATake Limits and Continuity Practice Exam A as a realistic first-unit Calculus I assessment covering limits, asymptotes, continuity, and the IVT.Practice examLimits and Continuity Practice Exam BTake Limits and Continuity Practice Exam B as a realistic first-unit Calculus I assessment covering limits, asymptotes, continuity, and the IVT.

Check your work

Exam answer keys

Finish an honest attempt, then compare one problem at a time. Every supplied exam answer is published and source-traced.

What This Book Is For

This is not a packet of lecture notes. It is meant to be the thing you read when the lecture moved too quickly, the textbook skipped three algebra steps, the homework answer says only "6," and every explanation online assumes you already understand the part you are trying to learn.

A student who can do the prerequisite algebra in the diagnostic should be able to use this unit to learn the first major topic of Calculus I from beginning to end. The unit is designed to support three levels of understanding at the same time:

• Plain-language understanding. What the idea means before the notation begins. • Homework competence. A repeatable method for solving the kinds of problems assigned in a first calculus course. • Exam readiness. Enough conceptual and algebraic control to handle unfamiliar versions of familiar problems without copying a pattern blindly.

Every major concept therefore appears in four forms:

• a plain-language explanation that assumes no prior calculus vocabulary; • a formal mathematical statement; • a fully worked example with no important algebra steps omitted; • practice organized from warm-up to exam level.

Concept

Think of this book as a patient tutor who never gets annoyed when you ask, "Why did that denominator disappear?" The answer should be visible on the page. If a solution jumps from line one to line five, it has failed at its job, regardless of how elegant the author felt while writing it.

How to Study With This Unit

Do not read mathematics the way you read a news article. A worked solution only becomes useful when you attempt the next move before seeing it.

For each worked example:

• Cover the solution. • Write down what direct substitution gives. • Name the obstacle: ordinary value, 0/00/0, division by zero, infinity over infinity, a jump, or something else. • Choose a method before uncovering the next line. • Compare your work with the solution and identify the first point where your reasoning differs.

For each exercise set, use three passes:

• Pass 1: Learn. Use the section and check answers after small groups of problems. • Pass 2: Remember. Return later and work without notes. • Pass 3: Perform. Work a mixed set under a time limit, with no labels telling you which method to use.

Summary

Looking at a solution and thinking "that makes sense" is not the same as being able to produce the solution. Recognition feels like knowledge because the page is doing half the thinking for you. Practice removes the page.

Suggested Pacing

The unit can be used as a two-week intensive review or a four-week first course unit.

Reference table
SessionMain workMinimum practice
1Average change, instantaneous change, basic limit languageSection 1 warm-ups 1--10
2Tables, graphs, function value versus limitSection 1 core 11--24
3One-sided limits and failure modesSection 1 exam practice 25--40
4Direct substitution and limit lawsSection 2 warm-ups 1--16
5Factoring and cancellationSection 2 core 17--34
6Radicals, complex fractions, absolute valuesSection 2 core 35--54
7Squeeze Theorem and trig limitsSection 3 exercises 1--38
8Infinite limits and vertical asymptotesSection 4 exercises 1--26
9Limits at infinity and radicalsSection 4 exercises 27--50
10Continuity and discontinuitySection 5 exercises 1--26
11Parameter problems and IVTSection 5 exercises 27--52
12Formal definition or optional honors trackSection 6 selected exercises
13Cumulative reviewSection 7 review set
14Practice exam and correctionPractice Exam A or B

Source & rights

Original instruction with traceable references.

The exposition is original. No Active Calculus exercise is reproduced verbatim. Public-domain examples were modernized and recomposed when used as inspiration.

The verified handoff declares original composition and requires owner provenance review. BetterGrades-original material remains separate from public-domain references; no source textbook PDF is published here.

Vocab
Limit
Math glossaryLimit
limxaf(x)=L\lim_{x\to a}f(x)=L

The value a function approaches as its input approaches a target.

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Function
Math glossaryFunction
y=f(x)y=f(x)

A rule or relation assigning exactly one output to each allowed input.

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Continuity
Math glossaryContinuity
limxaf(x)=f(a)\lim_{x\to a}f(x)=f(a)

At a point, the function value exists and equals the limit there.

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Domain
Math glossaryDomain
domf\operatorname{dom}f

The set of permitted input values.

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Math glossary