A decaying quantity obeys with .

PHYSICS · Multi-part · Fermi University Physics · Mathematical Methods for Physics · Numerical and computational mathematics · Numerical and computational mathematics

Error, Chance and the Machine, Ch Ordinary differential equations: order, stability and stiffness

Problem

A decaying quantity obeys y′=λyy' = \lambda y with λ=−50 s−1\lambda = -50\,\mathrm{s^{-1}}. ((a)) Find the largest step hh for which forward Euler's method is linearly stable on this equation. ((b)) State whether backward Euler suffers any such step restriction, and give the value of its stability function R(z)R(z) as z→−∞z \to -\infty, explaining what this value means for a fast-decaying component.

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