Variation 1 · answer guide
Differentiation techniques — Power 3/2 denominator
Question
(i) Differentiate . Hence,
(ii) Use to evaluate .
This practice question was inspired by Question 13(a) 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: apply product, chain or quotient rules carefully, simplifying only after differentiating.(i) .
- Finish the calculation, then check that the result meets the question’s conditions.Using part (i), (ii) , limits to .
- State the final answer clearly in the form the question requested.Integrand simplifies to after cancellation: .
Common mistake: changing so many features that the new example no longer tests the same mathematical idea.
Verification: Antiderivative check: from to gives .
Any mark labels are a TestMum study aid, not an official NESA marking allocation.
← Back to 2020 HSC Extension 1 paper Question 13(a)