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Find the local maximum and minimum.

Read the idea, work independently, then explain what changed.

TOPIC 01

2022 JM02

These are local, not global, extrema of the cubic.

Try it. Leave your reasoning visible.

Use one hint at a time. A correction explains what changed, not just the final answer.

01 / Standard#Your turn

Find the local maximum and minimum.

f(x)=x3−3x2+2f(x)=x^3-3x^2+2

Official paper · jm02-2022 · 2(a)(iii) · PDF 4

Official original and suggested answers ↗ · Suggested answer PDF page 9

Skills and prerequisite lessons

Working and explanation

BUILD THE REASONING

Hint 1
Solve 3x(x−2)=0.
Hint 2
Read the derivative sign changes.
Worked solution
  1. Derivative signs across 0,2 are +,−,+.

    f′(x)=3x(x−2)f'(x)=3x(x-2)
  2. Evaluate the corresponding function values.

    f(0)=2 (local maximum),f(2)=−2 (local minimum)f(0)=2\text{ (local maximum)},\quad f(2)=-2\text{ (local minimum)}

Local maximum 2 at x=0; local minimum −2 at x=2.

Checks and common pitfalls: These are local, not global, extrema of the cubic.

Reasoning checklist · self / teacher assessment
  • Teaching assessment checklist, independently authored. Use the original paper for official marks.
  • Derivative signs across 0,2 are +,−,+.
    f′(x)=3x(x−2)f'(x)=3x(x-2)
  • Evaluate the corresponding function values.
    f(0)=2 (local maximum),f(2)=−2 (local minimum)f(0)=2\text{ (local maximum)},\quad f(2)=-2\text{ (local minimum)}

Think first. Reveal a hint when the class is ready.

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Curriculum and source notes ↗