Calculus I · Limits and Continuity · exam
Limits and Continuity Practice Exam A
Answer key published
Finish first. Then check every answer.
The complete key is online, numbered to match this exam, and linked to the verified source appendix.
Practice Examination A
Suggested time: 75 minutes. Calculator: none unless your course normally permits one. Show reasoning; unsupported answers may receive little credit.
Part I: Concepts, 20 points
A graph approaches from both sides at , but the filled point is . State and the limit. Explain the distinction.
Show answer
, while the limit is . The filled point gives the first; nearby graph behavior gives the second.
Answer 1 from the source-traced unit appendix.State all three continuity conditions at .
Show answer
Defined value, existing two-sided limit, equality between them.
Answer 2 from the source-traced unit appendix.Explain why is indeterminate rather than equal to zero.
Show answer
It records simultaneous numerator and denominator convergence to zero but does not determine their relative rates.
Answer 3 from the source-traced unit appendix.State what the Intermediate Value Theorem guarantees and what it does not guarantee.
Show answer
IVT guarantees at least one attained intermediate value under continuity; it does not calculate or prove uniqueness.
Answer 4 from the source-traced unit appendix.Part II: Finite limits, 35 points
Show answer
.
Answer 5 from the source-traced unit appendix.Show answer
Factor and cancel to obtain ; answer .
Answer 6 from the source-traced unit appendix.Show answer
Rationalization gives ; answer .
Answer 7 from the source-traced unit appendix.Show answer
Combine fractions to obtain ; at , answer .
Answer 8 from the source-traced unit appendix.Show answer
.
Answer 9 from the source-traced unit appendix.Show answer
Squeezed between and ; answer .
Answer 10 from the source-traced unit appendix.Show answer
Left , right ; answer .
Answer 11 from the source-traced unit appendix.Part III: Infinite behavior, 25 points
Find both one-sided limits of at .
Show answer
Numerator approaches ; denominator changes sign. Left , right .
Answer 12 from the source-traced unit appendix.Show answer
.
Answer 13 from the source-traced unit appendix.Show answer
.
Answer 14 from the source-traced unit appendix.Find the hole, vertical asymptote, and horizontal asymptote of .
Show answer
Hole at , vertical asymptote , horizontal asymptote .
Answer 15 from the source-traced unit appendix.Part IV: Continuity and existence, 20 points
Find so is continuous at .
Show answer
, so .
Answer 16 from the source-traced unit appendix.Use IVT to show has a root in .
Show answer
The polynomial is continuous; values at are , so a root exists.
Answer 17 from the source-traced unit appendix.Give a valid in terms of for .
Show answer
.
Answer 18 from the source-traced unit appendix.After the explanation
Use the section idea
Can you diagnose the limit type and justify a method before beginning the algebra?
A mixed problem is a classification task before it is a calculation: direction, substitution result, structure, and required conclusion determine the route.
Name the limit type and first legal move in a margin note, then solve and check whether the conclusion matches the graph or sign behavior.
Pattern matching without diagnosis makes similar-looking problems blur together and hides whether the error was conceptual, algebraic, or strategic.
You are exam-ready when you can choose a method without a section label, explain the choice, and correct a miss by naming its exact cause.
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.