(adsbygoogle = window.adsbygoogle || []).push({}); 1. The problem statement, all variables and given/known data

Find the constants A and B such that the function y = Asinx + Bcosx satisfies the differential equation y'' + y' - 2y = sinx

2. Relevant equations

None

3. The attempt at a solution

My attempt: y = Asin x + Bcosx

y' = Acosx - Bsinx

y'' = - Asin x - Bcosx

y'' + y' - 2y = sin x

- Asinx - Bcosx + Acosx - Bsinx - 2Asinx + 2Bcosx = sinx

- 3Asinx + Bcosx + Acosx - Bsinx = sinx...

I dont know if my working out is correct, but I couldnt figure out what to do from there.

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# Homework Help: Derivatives of trigonometric functions

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