Variation 3 · answer guide
Vectors — Equality case
Question
When does equality hold in ?
This practice question was inspired by Question 14(b) in the 2022 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
- State the final answer clearly in the form the question requested.Only when , because .
Common mistake: changing so many features that the new example no longer tests the same mathematical idea.
Verification: Strict uniqueness of the nearest point on the line.
Any mark labels are a TestMum study aid, not an official NESA marking allocation.
← Back to 2022 HSC Extension 1 paper Question 14(b)