Level 2 Calculus Walkthrough
2025 NCEA Level 2 Calculus Question 2(c)
2025 Paper — Rates of change and justifying when coffee was given
Walkthrough overview
What this question practises
This 2025 walkthrough is part of AS91262 — Apply calculus methods in solving problems.
Method: Differentiating, evaluating a rate, and using derivatives to justify the minimum turning point.
This is Question 2(c) from the 2025 NCEA Level 2 Calculus paper for AS91262 — Apply calculus methods in solving problems. Use the guided hints to practise the method before revealing the full working.
Calc.nz is an independent learning resource. Compare questions, diagrams, and assessment information with the official NZQA resources for AS91262.
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Learning summary
Review the method, not only the answer
This walkthrough helps you practise differentiating, evaluating a rate, and using derivatives to justify the minimum turning point. Use the hints to plan the method, then repeat the question without hints and check each step.
Common mistake to avoid
Finding a stationary value is only part of the argument; justify that it is the required minimum and respect the domain.
Continue practising
- All 2025 Calculus walkthroughs
- All AS91262 Calculus years
- Practise more questions using this skill: Stationary points and optimisation