Variation 3 · answer guide
Vector motion — Recover position
Question
A particle has and . Find .
This practice question was inspired by Question 13(c) in the 2025 NSW HSC Mathematics Extension 1 examination, © NESA. It is an original TestMum variation that practises the same mathematical idea, not an official NESA question.
Step by step
- Set up the solution: differentiate position to get velocity and acceleration, then translate the angle condition into a dot product.Integrate components: .
- Simplify the previous line carefully, keeping exact values where possible.Use .
- Finish the calculation, then check that the result meets the question’s conditions., .
- State the final answer clearly in the form the question requested.Final answer:
Common mistake: changing so many features that the new example no longer tests the same mathematical idea.
Verification: Differentiate the position and check the initial position.
Any mark labels are a TestMum study aid, not an official NESA marking allocation.
← Back to 2025 HSC Extension 1 paper Question 13(c)