Undetermined coefficients

  • #1
Hi there, I know that when I am to guess a solution to to a polynomial for g(t) that I guess Ax^n + Bx^n-1... when the highest power of the polynomial is n but what is my guess supposed to be if the power of n is negative?

ex.
y'' + 4y' + 4y = t^-2*e^(-2t)

so far my guess is,

A*e^(-2t)(B*?...)
 

Answers and Replies

  • #3
LCKurtz
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Hi there, I know that when I am to guess a solution to to a polynomial for g(t) that I guess Ax^n + Bx^n-1... when the highest power of the polynomial is n but what is my guess supposed to be if the power of n is negative?

ex.
y'' + 4y' + 4y = t^-2*e^(-2t)

so far my guess is,

A*e^(-2t)(B*?...)
To add to SteamKing's link, you don't even try undetermined coefficients if n is negative, because it won't work.
 

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