Question

Y''-6y'+9y=(3x-8) найти общее решение.

Answer 1

$y''-6y'+9y=(3x-8)\\\lambda^2-6\lambda+9=0\\(\lambda-3)^2=0\\\lambda_{1,2}=3\\Y=C_1e^{3x}+xC_2e^{3x}\\\hat{y}=Ax+B\\\hat{y}'=A\\\hat{y}''=0\\-6A+9Ax+9B=3x-8\\x|9A=3=\ \textgreater \ A=\frac{1}{3}\\x^0|-6A+9B=-8=\ \textgreater \ B=-\frac{2}{3}\\\hat{y}=\frac{x-2}{3}\\y=Y+\hat{y}=C_1e^{3x}+xC_2e^{3x}+\frac{x-2}{3}$