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Solve both parts and justify the conditions used. Part A: Determine whether the two claimed trigonometric values can occur together. Part B: A wheel has radius 8 m and its centre is 10 m above ground. Find the greatest passenger height.

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

TOPIC 01

Trigonometric functions: mixed assessment

A mixed assessment: identify the method, justify it and revise your reasoning.

What you will be able to explain

  • Connect the chapter skills without relying on the order of the exercises.

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

Solve both parts and justify the conditions used. Part A: Determine whether the two claimed trigonometric values can occur together. Part B: A wheel has radius 8 m and its centre is 10 m above ground. Find the greatest passenger height.

A: sin⁡θ=4/5,cos⁡θ=4/5\begin{gathered}\text{A: }\sin\theta=4/5,\quad\cos\theta=4/5\end{gathered}
  • Use the domain, units and sampling assumptions stated in the question.
  • Use the domain, units and sampling assumptions stated in the question.
Skills and prerequisite lessons

Working and explanation

BUILD THE REASONING

Hint 1
A: Use coordinates on the terminal ray and a positive radius.
Hint 2
B: Define the geometric or periodic quantities with units, then choose a trigonometric relation.
Worked solution
  1. Part A reasoning

  2. Use coordinates on the terminal ray and a positive radius.

  3. Calculate or simplify this relation.

    (4/5)2+(4/5)2=32/25≠1(4/5)^2+(4/5)^2=32/25\ne1
  4. Each value being individually between −1 and 1 is insufficient.

  5. Part B reasoning

  6. Define the geometric or periodic quantities with units, then choose a trigonometric relation.

  7. Calculate or simplify this relation.

    hmax⁡=(10)+8=18h_{\max}=(10)+8=18
  8. The corresponding minimum is 2 m, so the wheel remains above ground.

A: No, because their squared sum is not one. B: The requested value is 18.

Checks and common pitfalls: Each value being individually between −1 and 1 is insufficient. The corresponding minimum is 2 m, so the wheel remains above ground.

Reasoning checklist · self / teacher assessment
  • Solve part A with its stated restrictions.
  • Solve part B using an appropriate representation.
  • Give the reasoning and check conditions in both parts.

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

Focus on one question

Teacher preparation and assessment

Question sequence

  • Ask students to name the relevant condition before calculating.

Board plan

  • Compare valid methods and annotate their conditions.

Anticipated thinking

  • A correct final value may still hide a missing assumption.

Assessment checklist

  • Check the method, conditions, reasoning and interpretation separately.

No sign-in. Work stays in this browser. Export before clearing browser data. Written reasoning is assessed with a checklist.

Curriculum and source notes ↗