MATH221 · Annotated SlidesChapter 3 — Interpolation and the Lagrange Polynomial
Chapter 3 · Annotated slides

Interpolation and the Lagrange Polynomial

Interpolation and the Lagrange interpolating polynomial, its error formula, and worked examples.

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Slide 1: Slide 1
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    Slide 2: Lagrange Interpolating Polynomials
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    1. Lagrange: P(x) = Σ f(xₖ)Lₖ(x), Lₖ(x) = Π_{i≠k} (x − xᵢ)/(xₖ − xᵢ). Degree ≤ n through n + 1 points.
    2. Error: f(x) − P(x) = f⁽ⁿ⁺¹⁾(ξ)/(n + 1)! · Π(x − xᵢ).
    🎯 How this can come up · 1 question
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    Find the linear Lagrange polynomial through (2, 4) and (5, 1).

    Slide 3: Lagrange Interpolating Polynomials
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      Slide 4: Example 1
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            Slide 7: Example 2
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              Slide 8: Solution
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                  Slide 10: Exercise Set 3.1
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                      Slide 12: Exercise
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