Unit 1: Limits & Continuity AP Calculus BC (Full Guide 2026)
Last Updated: March 2026

Unit 1 (Limits & Continuity) is the foundation of AP Calculus BC.
If you master this unit, everything else becomes easier β especially derivatives and integrals.
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π Unit Weight in Exam
Limits & Continuity contributes around 4%β7% of the exam, but it is used in almost every other unit.
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π Key Concepts You Must Know
1. What is a Limit?
A limit is the value a function approaches as x approaches a certain number.
- Left-hand limit
- Right-hand limit
- Limit exists if both are equal
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2. Types of Limits
- Finite limits
- Infinite limits
- Limits at infinity
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3. Continuity
A function is continuous if:
- f(a) is defined
- Limit exists
- Limit = f(a)
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π Important Formulas & Rules
- Limit laws (sum, product, quotient)
- Squeeze theorem
- Intermediate Value Theorem
π Official syllabus:
College Board AP Calculus
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π Sample FRQ (Exam Style)
Evaluate:
lim (xβ2) (xΒ² – 4)/(x – 2)
Solution:
- Factor: (x-2)(x+2)
- Cancel (x-2)
- Answer = 4
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π Practice PYQs
- Evaluate limits using algebraic simplification
- Analyze graphs for continuity
- Identify discontinuities
π Practice more here:
StudyHelper
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π¨ Common Mistakes in Unit 1
- Not checking left-hand and right-hand limits
- Forgetting to simplify expressions
- Misinterpreting graphs
π Full mistake guide:
Common Mistakes
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π₯ Best Strategy to Master Unit 1
- Understand concepts (donβt memorize)
- Practice limits daily
- Solve FRQs
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π Internal Links
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π Smart Learning Method
Instead of just reading notes, use:
π StudyHelper
- Practice limits questions
- Get instant feedback
- Improve faster
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π― Final Thoughts
Limits & Continuity may seem simple, but they are the base of calculus.
Master this unit and the rest of the course becomes much easier.
Start practicing now β
StudyHelper.io