Variation of Parameters - Description of Method

Description of Method

Given an ordinary non-homogeneous linear differential equation of order n

(i)

let be a fundamental system of solutions of the corresponding homogeneous equation

(ii)

Then a particular solution to the non-homogeneous equation is given by

(iii)

where the are continuous functions which satisfy the equations

(iv)

By substituting (iii) into (i) and applying (iv) it follows that

(v)


The linear system (v) of n equations can then be solved using Cramer's rule yielding

where is the Wronskian determinant of the fundamental system and is the Wronskian determinant of the fundamental system with the i-th column replaced by

The particular solution to the non-homogeneous equation can then be written as

Read more about this topic:  Variation Of Parameters

Famous quotes containing the words description of, description and/or method:

    “I was here first introduced to Joe.... He was a good-looking Indian, twenty-four years old, apparently of unmixed blood, short and stout, with a broad face and reddish complexion, and eyes, methinks, narrower and more turned up at the outer corners than ours, answering to the description of his race. Besides his underclothing, he wore a red flannel shirt, woolen pants, and a black Kossuth hat, the ordinary dress of the lumberman, and, to a considerable extent, of the Penobscot Indian.”
    —Henry David Thoreau (1817–1862)

    “An intentional object is given by a word or a phrase which gives a description under which.”
    —Gertrude Elizabeth Margaret Anscombe (b. 1919)

    “You that do search for every purling spring
    Which from the ribs of old Parnassus flows,
    And every flower, not sweet perhaps, which grows
    Near thereabouts into your poesy wring;
    You that do dictionary’s method bring
    Into your rhymes, running in rattling rows;”
    —Sir Philip Sidney (1554–1586)