Variation of Parameters

Jan 1, 2021 · 1 min read

Summary

Our quest on finding a particular solution of

$$ x^{\prime \prime}(t)+p(t) x^{\prime}(t)+q(t) x(t)=f(t) $$

continues. Earlier, we used the Method of Undetermined Coefficients to do that. That method had two restrictions

  • the coefficients $p(t)$ and $q(t)$ had to be constants (the ODE is constant-coefficient),
  • the forcing $f(t)$ had to be from special families of functions such as exponentials, trigonometric, polynomials.

With the Variation of Parameters, we will lift these restrictions.

Full Set of Lecture Notes

The notes for this lecture are available here.