Skip to content
Marlbridge

AP® Calculus AB · Unit 5 · Topic 5.9

Connecting a Function, Its First Derivative, and Its Second Derivative: Topic Checklist (Calculus AB 5.9)

Specific “I can…” statements for linking the graphs of f, f′ and f″, each tied to the guide section and practice question that shows whether you can do it.

Work through the list without notes or a calculator. If you cannot do a statement, follow its link, then come back. Guide = study guide; Practice = practice questions. This topic is shared by Calculus AB and Calculus BC.

Understanding

  • I can explain why the graph of f′ carries two kinds of information about f: its sign gives direction and its rising or falling gives concavity. (Guide: “One story told by three graphs”; Practice Q1)
  • I can say what a graph of f″ tells me about f and f′, and what it cannot tell me. (Guide: “Reading a graph of f″”; Practice Q2)
  • I can explain why the height of f′ is a slope of f and never a value of f. (Guide: “Reading a graph of f′”)

Skills

  • I can find the intervals where f increases, decreases, is concave up and is concave down from a graph of f′. (Guide: Worked example 1; Practice Q3, Q6(b))
  • I can locate and classify relative extrema of f from where f′ crosses the axis. (Guide: Worked example 1(b); Practice Q6(a))
  • I can locate inflection points of f as turning points of f′ or sign changes of f″. (Guide: Worked examples 1 and 3; Practice Q4, Q6(c))
  • I can find a value of f″ as the slope of a straight part of the graph of f′. (Guide: Worked example 1(e); Practice Q6(d))
  • I can decide which of three graphs is f, f′ and f″ by lining up zeros with turning points. (Guide: Worked example 2; Practice Q5(a))

Reasoning

  • I can justify an extremum or inflection point with a sentence that names f′ or f″ and says how it changes. (Guide: “Justifying a conclusion”; Practice Q5(b), Q6(a))
  • I can explain why a zero of f″, or a point where f″ does not exist, is not automatically an inflection point. (Guide: “Common misconceptions”; Practice Q4, Q6(e))
  • I can use sign facts about f″ and a few values of f′ to work out where f is increasing or decreasing. (Practice Q7)

All ticked? Move on to Topic 5.10, Introduction to Optimization Problems, or return to the Calculus AB roadmap or the Calculus BC roadmap.

AP® and Advanced Placement® are trademarks registered by the College Board, which is not affiliated with, and does not endorse, this website. Marlbridge is an independent tuition provider. It is not an authorized AP course provider, an AP school or an exam centre, and these resources are not official College Board materials. Reading them or doing simulations does not meet the laboratory requirement of an AP science course.