Differential Equations › Section I · Partial differential equations › Topic I.4

Separation of variables

A partial differential equation is hard; two ordinary ones are familiar. Separation of variables guesses a solution that is a product of one-variable functions, and that guess splits the heat, wave and Laplace equations into ODEs you already know how to handle.

In this topic

  • The idea: guess a product
  • Separating the heat equation
  • Why both sides equal a constant
  • Boundary conditions carry over
  • Worked example: a bar with both ends at zero
  • Separating the wave equation
  • Worked example: a string with fixed ends
  • Separating Laplace's equation
  • Worked example: a bar losing heat through its sides
  • When separation fails
  • Common mistakes to avoid
  • Key takeaways

This topic is part of Wuanberri Pro. Checking your access…

← Previous topicNext topic →