Variation 2 · answer guide
Vectors — Geometric meaning
Question
Vectors and start at the same point and end at and . Which statement describes ?
This practice question was inspired by Question 6 in the 2020 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: write the vector relationship component by component, then use a dot product, magnitude or scalar multiple as required..
- Finish the calculation, then check that the result meets the question’s conditions.So
runs from to . - Match the result to the choices and state the correct option.Therefore option A is correct.
Common mistake: changing so many features that the new example no longer tests the same mathematical idea.
Verification: Position-vector identity:
Any mark labels are a TestMum study aid, not an official NESA marking allocation.
← Back to 2020 HSC Extension 1 paper Question 6