Variation 3 · answer guide
Differential equation — With initial condition
Question
Solve with , giving in terms of .
This practice question was inspired by Question 11(e) 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: separate or integrate the differential equation, include the constant, then use the initial condition.General: .
- Finish the calculation, then check that the result meets the question’s conditions.At , : .
- State the final answer clearly in the form the question requested..
Common mistake: changing so many features that the new example no longer tests the same mathematical idea.
Verification: When , ; derivative check holds.
Any mark labels are a TestMum study aid, not an official NESA marking allocation.
← Back to 2020 HSC Extension 1 paper Question 11(e)