Level 3 Integration Walkthrough

2024 NCEA Level 3 Integration Question 1(e)

2024 Paper

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Question

The graph below shows the curves \(y=3\sec^2x\) and \(y=2\tan^2x\).

1 x = 1 y = 3 sec²x y = 2 tan²x x y Diagram is not to scale

Find the area of the shaded region enclosed by the two curves, \(x=1\), and the \(y\)-axis.

You must use calculus and show the results of any integration needed to solve the problem.

The diagram is shown in its initial state. JavaScript adds any interactive controls and later walkthrough visuals.

First walkthrough idea

Hint to try first

Between \(x=0\) and \(x=1\), the top curve is \(y=3\sec^2x\) and the bottom curve is \(y=2\tan^2x\).

Step 1

Identify top minus bottom

Area between curves is top minus bottom over the interval \(0\le x\le1\).

Show the first step’s working

Area between curves is top minus bottom over the interval \(0\le x\le1\).

Key result

\[ \int_0^1\left(3\sec^2x-2\tan^2x\right)\,dx \]

Walkthrough overview

What this question practises

This 2024 walkthrough is part of AS91579 — Apply integration methods in solving problems.

Method: Finding area between sec² and tan² curves.

This is Question 1(e) from the 2024 NCEA Level 3 Integration paper for AS91579 — Apply integration 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 AS91579.

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Learning summary

Review the method, not only the answer

This walkthrough helps you practise finding area between sec² and tan² curves. Use the hints to plan the method, then repeat the question without hints and check each step.

Common mistake to avoid

Check intersections, signs, and whether the question asks for signed area or total geometric area.

Continue practising