Physics I / Graphs, approximation, and numerical sense
Practice question · Put in order

Order the steps in one iteration of Newton's method for root-finding.

Hints
  1. Each step needs both the function value and the slope at the current guess.
  2. The updated guess is produced last and feeds the next iteration.
Show the answer
  1. Start with an initial guess x0x_{0} close to the root
  2. Evaluate f(x0x_{0}) and f'(x0x_{0})
  3. Compute the next iterate: x1=x0f(x0)/f(x0)x_{1} = x_{0} - f(x_{0})/f'(x_{0})
  4. Repeat until |xnx_{n}₊₁ − xnx_{n}| is smaller than the desired tolerance
Why

Newton's method has quadratic convergence near simple roots.

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