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Undetermined coefficients help

  • Thread starter brungus
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  • #1
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Hi, new here, im looking for some help on this homework problem. pretty sure you need to separate yp into 2 parts?

anyways, use method of undetermined coeff. to solve

y" + y = x*cos(x) - cos(x)

thanks.
 

Answers and Replies

  • #2
Hootenanny
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Hi, new here, im looking for some help on this homework problem. pretty sure you need to separate yp into 2 parts?

anyways, use method of undetermined coeff. to solve

y" + y = x*cos(x) - cos(x)

thanks.
Hi brungus and welcome to PF,

I'm assuming that you've found the homogeneous solution. For the particular solution, notice that we have a product of two functions of x. How does one usually differentiate a product of two functions?

Also for future reference, we have Homework Forums where you can post all your textbook questions :smile:.
 
  • #3
HallsofIvy
Science Advisor
Homework Helper
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Why have you not shown any work? In particular, what do you get for the general solution to the corresponding homogeneous equation?
 

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