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  3. AP Calculus - 2018 FRQ Review: DEs, Slope Fields & Rates

ap calculus - 2018 frq review: des, slope fields & rates

originally streamed in 2018 with Amy Dunn-RuizTeacher
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Review the 2018 AP Calculus FRQ with step-by-step solutions for derivatives, integrals, slope fields, and separable differential equations. This walkthrough breaks down each free response question to help you prepare for your AP Calc AB or BC exam. ...more

curriculum note

This video briefly discusses the 2020 COVID at-home exam logistics (no printer, submitting photos) that no longer apply; the 2018 FRQ problems and all mathematical content remain valid for exam practice.

covered in this stream

units
AP Calculus AB/BC ExamsUnit 7 – Differential EquationsUnit 8 – Applications of IntegrationUnit 4 – Contextual Applications of Differentiation
topics
2018 Free Response Questions2018 FRQ Review7.3 Sketching Slope Fields7.4 Reasoning Using Slope Fields7.6 Finding General Solutions Using Separation of Variables7.7 Finding Particular Solutions Using Initial Conditions and Separation of Variables4.6 Approximating Values of a Function Using Local Linearity and Linearization8.3 Using Accumulation Functions and Definite Integrals in Applied Contexts

timestamps

  • 0:00

    Introduction and Overview

  • 0:33

    Calculator-Friendly Problems

  • 1:05

    No-Calculator Problems

  • 1:37

    Starting Problem 6

  • 2:09

    Slope Field Explanation

  • 3:12

    Reviewing Slope Fields

  • 4:19

    Slope Field Drawing Tips

  • 5:20

    Example Slope Calculation

  • 6:23

    Estimating Slopes Visually

  • 7:31

    Exam Logistics Discussion

  • 8:01

    Sketching Solution Curves

  • 9:05

    Solution Curve Through (0,2)

  • 10:06

    Solution Curve Through (1,0)

  • 11:09

    Particular Solution Intro

  • 12:13

    Tangent Line Equation

  • 13:13

    Point-Slope Form

  • 14:15

    Slope Calculation at Point

  • 15:17

    Linear Approximation Equation

  • 16:19

    Approximating f(0.7)

  • 17:50

    Approximation Result

  • 19:21

    Simplifying Fractions

  • 20:52

    Tying to Graph

  • 21:54

    Solving Particular Solution

  • 22:27

    Separable Differential Equations

  • 24:02

    Separating Variables

  • 25:35

    Identifying Separable DEs

  • 27:07

    Integrating Both Sides

  • 28:40

    Combining Constants

  • 29:42

    Solving for y

  • 31:14

    Plugging Initial Condition

  • 32:49

    Finding Constant Value

  • 34:24

    Particular Solution Equation

  • 35:59

    Reciprocal and Simplifying

  • 37:35

    Constant Sign Changes

  • 38:38

    Transition to Next Problem

  • 39:40

    Problem 1 Overview

  • 40:43

    Rate Functions Explained

  • 42:15

    Part A: Entering People

  • 43:49

    Integrating Rate In

  • 45:24

    Calculator Integration

  • 47:28

    Answering in Context

  • 49:35

    Part B: People at t=300

  • 51:08

    Combining Rates Integral

  • 52:44

    People in Line Calculation

  • 53:45

    Part C: Time Line Empties

  • 55:19

    Simple Rate Division Method

  • 56:54

    Accumulation Integral Setup

  • 58:28

    Solving for Time x

  • 1:00:32

    Part D: Minimum People

  • 1:02:06

    Graphing Rate Change

  • 1:03:42

    Finding Relative Minimum

  • 1:05:15

    Calculating Time of Min

  • 1:06:49

    People at Minimum Time

  • 1:08:20

    Practice Tips

  • 1:09:23

    Possible Exam Topics

  • 1:10:27

    BC FRQ Discussion

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Study GuidesFRQs + AI ScoringAP Essay Grader for StudentsAI Grading for TeachersPractice QuestionsGlossaryScore Calculators

Company

What's New?PricingBulk DiscountsTestimonialsFAQsEmail us

Resources

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history

🌎 ap world history🇺🇸 ap us history🇪🇺 ap european history

social science

✊🏿 ap african american studies🗳️ ap comparative government🚜 ap human geography💶 ap macroeconomics🤑 ap microeconomics🧠 ap psychology👩🏾‍⚖️ ap us government

english & capstone

✍🏽 ap english language📚 ap english literature🔍 ap research💬 ap seminar

arts

🎨 ap art & design🖼️ ap art history🎵 ap music theory

science

🧬 ap biology🧪 ap chemistry♻️ ap environmental science🎡 ap physics 1🧲 ap physics 2💡 ap physics c: e&m⚙️ ap physics c: mechanics

math & computer science

🧮 ap calculus ab♾️ ap calculus bc📐 ap precalculus📊 ap statistics💻 ap computer science a⌨️ ap computer science p

world languages

🇨🇳 ap chinese🇫🇷 ap french🇩🇪 ap german🇮🇹 ap italian🇯🇵 ap japanese🏛️ ap latin🇪🇸 ap spanish language💃🏽 ap spanish literature

go beyond AP

high school exams

✏️ PSAT🎓 Digital SAT🎒 ACT

honors classes

🍬 honors algebra II🫀 honors anatomy🐇 honors biology👩🏽‍🔬 honors chemistry💲 honors economics📐 honors geometry⚾️ honors physics📏 honors pre-calculus📊 honors statistics🗳️ honors us government🇺🇸 honors us history🌎 honors world history

college classes

👩🏽‍🎤 arts👔 business🎤 communications🏗️ engineering📓 humanities➗ math🧑🏽‍🔬 science💶 social science

hs classes

🏛️ alabama history⛰️ appalachian studies🌴 california history🌍 earth science🌐 ethnic studies🐊 florida history🍑 georgia history🌎 global studies🌺 hawaiian studies📰 journalism🪶 native american studies🌵 new mexico history🤠 oklahoma history⚗️ physical science🎙️ speech and debate🤝 texas government🤠 texas history🌲 washington state history🕊️ world religions
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© 2026 Fiveable Inc. All rights reserved.

AP® and SAT® are trademarks registered by the College Board, which is not affiliated with, and does not endorse this website.