TestMum
← 2021 HSC Extension 1 paper Question 13(a)

Variation 3 · answer guide

Volume of revolution — Washer setup

Question

Express the sculpture volume as a single washer integral in for the original problem, then evaluate.

This practice question was inspired by Question 13(a) 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

  1. Set up the solution: identify the radius and use the disk or washer formula with the correct variable and bounds.For : solid disk radius . For : washer outer , inner .
  2. 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: Same answer .

Any mark labels are a TestMum study aid, not an official NESA marking allocation.

← Back to 2021 HSC Extension 1 paper Question 13(a)