4.2/



Extrapolation

  1. What?
    • Extrapolation is used to
    • Extrapolation can be applied whenever
    • Suppose that for each number \(h \neq 0\) we have a formula \(N_1(h)\) that approximates an unknown constant \(\ \ \ \ \ \ \ \\), and that the truncation error involved with the approximation has the form,
      \(\ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \\)
    • The truncation error is \(\ \ \ \ \ \ \ \ \ \ \ \ \ \\) \(\ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \\)
      \(\ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \\)
      and, in general,
      \(\ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \\)
    • The object of extrapolation is
  2. Why?
  3. The \(\mathcal{O}(h)\) formula for approximating \(M\):

    The First Formula:

    The Second Formula:

  4. The \(\mathcal{O}(h^2)\) approximation formula for M:
  5. When to apply Extrapolation?
  6. The \(\mathcal{O}(h^4)\) formula for approximating \(M\):
  7. The \(\mathcal{O}(h^6)\) formula for approximating \(M\):
  8. The \(\mathcal{O}(h^{2j})\) formula for approximating \(M\):
  9. The Order the Approximations Generated:

Deriving n-point Formulas with Extrapolation

  1. Deriving Five-point Formula: