Find the general solution of the nonhomogeneous differential equation x^2y''-2y=3(x^2) -1, (x>0).

(I have already verified that y1=1/x is a solution of the differential equation x^2y''-2y=0).

Respuesta :

Answer:

G.S=[tex]C_1\frac{1}{x}+C_2x^2+x^2logx+\frac{1}{2}[/tex]

Step-by-step explanation:

We are given that non-homogeneous differential equation

[tex]x^2y''-2y=3(x^2)-1[/tex]

It is Cauchy Euler equation

Substitute x=e^t  x>0

Auxillary equation

[tex]D'(D'-1)-2=0[/tex]

[tex]D'^2-D'-2=0[/tex]

[tex](D'-2)(D'+1)=0[/tex]

[tex]D'-2=0 \implies D'=2[/tex]

[tex]D'+1=0\implies D'=-1[/tex]

Complementary solution

[tex]y=C_1e^{-t}+C_2e^{2t}[/tex]

[tex]y=C_1\frac{1}{x}+C_2x^2[/tex]

Particular solution

[tex]y_p=\frac{3e^{2t}}{D'^2-D'-2}-\frac{e^{0t}}{D'^2-D'-2}[/tex]

[tex]y_p=te^{2t}+\frac{1}{2}=x^2logx+\frac{1}{2}[/tex]

G.S=[tex]C_1\frac{1}{x}+C_2x^2+x^2logx+\frac{1}{2}[/tex]

Hence, general solution G.S=[tex]C_1\frac{1}{x}+C_2x^2+x^2logx+\frac{1}{2}[/tex]