MathsYears 12–13Numerical Methods

Numerical integration (trapezium rule)

Approximate definite integrals using the trapezium rule; estimate and bound errors

What you'll learn

  1. 1

    Imagine you want to find the area under a curve, like the path of a rollercoaster 🎢. The trapezium rule chops the area into strips that look like trapeziums (shapes with two parallel sides).

  2. 2

    What shape does each strip look like in the trapezium rule?

  3. 3

    Let's estimate the area under y = x² from x = 1 to x = 3 using 2 strips.

  4. 4

    Now you try! Estimate the area under y = x² from x = 0 to x = 2 using 2 strips.

  5. 5

    Using the trapezium rule with 2 strips from x=0 to x=2 for y=x², what is the estimated area? (Width=1, y-values: 0, 1, 4)

  6. 6

    Let's try one with 3 strips under y = 2x from x = 0 to x = 3.

  7. 7

    For y = 2x from x=0 to x=3 with 3 strips, the estimated area is 9. What is the actual exact area (it's a triangle)?

Practise Numerical integration (trapezium rule) with Whizlo

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