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Solve both parts and justify the conditions used. Part A: Explain why the sine rule in an SSA problem may give two triangles. Part B: Do equal magnitudes guarantee equal vectors? Give a counterexample.

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

TOPIC 01

Plane vectors and applications: 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: Explain why the sine rule in an SSA problem may give two triangles. Part B: Do equal magnitudes guarantee equal vectors? Give a counterexample.

A: sin⁡B=s,0<s<1B: ∣a∣=∣b∣=10\begin{gathered}\text{A: }\sin B=s,\quad0<s<1\\\text{B: }|\mathbf a|=|\mathbf b|=10\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: Translate the geometry or physical quantity into vectors and check angle conventions.
Hint 2
B: Separate magnitude, direction and position; compare vectors by displacement.
Worked solution
  1. Part A reasoning

  2. Translate the geometry or physical quantity into vectors and check angle conventions.

  3. Calculate or simplify this relation.

    sin⁡B=sin⁡(180∘−B)\sin B=\sin(180^{\circ}-B)
  4. A supplementary candidate is discarded if the angle sum makes it impossible.

  5. Part B reasoning

  6. Separate magnitude, direction and position; compare vectors by displacement.

  7. Calculate or simplify this relation.

    ∣(10,0)∣=∣(0,10)∣=10|(10,0)|=|(0,10)|=10
  8. The two perpendicular nonzero vectors cannot be equal.

A: Both B and 180°−B have the same sine; each must be checked against the remaining angle and side conditions. B: No: (10,0) and (0,10) have different directions.

Checks and common pitfalls: A supplementary candidate is discarded if the angle sum makes it impossible. The two perpendicular nonzero vectors cannot be equal.

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 ↗