Paper 3 · Module
Numerical solution of equations
Locating roots: sketches and sign changes
Most equations have no exact solution. Before you can approximate a root you need to know how many there are and roughly where: sketch two graphs to count them, then trap each one with a change of sign.
≈ 35 minFixed-point iteration
Feed a number into a formula, feed the answer back in, and repeat. When the values settle down they settle on a root. This lesson is the engine of every P2 and P3 numerical question.
≈ 40 minRearrangements, staircases and cobwebs
One equation can be rearranged into in many ways, and they do not all work. See why some iterations close in on a root, some zigzag towards it, and some run away, and learn to find the equation a limit satisfies.
≈ 40 min