Variation 3 · answer guide
Differential equation — Numerical check
Question
Evaluate to the nearest thousand.
This practice question was inspired by Question 14(b) in the 2021 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: separate or integrate the differential equation, include the constant, then use the initial condition..
- Simplify the previous line carefully, keeping exact values where possible.Numerator .
- Finish the calculation, then check that the result meets the question’s conditions.Denominator .
- State the final answer clearly in the form the question requested. (nearest thousand ; paper says approximately ).
Common mistake: changing so many features that the new example no longer tests the same mathematical idea.
Verification: Matches the exam approximation.
Any mark labels are a TestMum study aid, not an official NESA marking allocation.
← Back to 2021 HSC Extension 1 paper Question 14(b)