my homework asks us to find the particular solution to a second Order non-homogeneous differential equation with given y1 and y2 in which we are supposed to use to use along with the formula of Variation of Parameters.

What have i tried? Well, I've tried using Method of Undetermined Coefficients to check my work but i keep getting a different answer, and I've confirmed that the second particular solution(Through Undetermined Coefficients) I've obtained is correct.

Problem:What is the mistake i am making when i am using Variation of Parameters? I keep getting $\frac{-xcos + sinx}{2}$ when the CORRECT answer is $\frac{-xcosx}{2}$ as seen through the Method of Undetermined Coefficients

Thank you all.

Variation Of Parameters

Method of Undetermined Coefficients


closed as unclear what you're asking by Claude Leibovici, Sharkos, Andrew, kimchi lover, Namaste Jan 26 '18 at 23:58

Please clarify your specific problem or add additional details to highlight exactly what you need. As it's currently written, it’s hard to tell exactly what you're asking. See the How to Ask page for help clarifying this question. If this question can be reworded to fit the rules in the help center, please edit the question.

  • 1
    $\begingroup$ The least you could do is to make your pictures legible (and horizontal). Better yet, please use MathJax to type out every relevant equation to point out (1) the problem statement (2) your solution (3) which part you feel contains a mistake and what exactly are you unsure about $\endgroup$ – Yuriy S Jan 26 '18 at 8:41

The $\sin x/2$ bit is part of the homogeneous solution, so it would normally be dropped.


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