The indicated function y1(x) is a solution of the given differential equation. Use reduction of order or formula (5) in Section 4.2, y2 = y1(x) e−∫P(x) dx y 2 1 (x) dx (5) as instructed, to find a second solution y2(x). y'' − 4y' + 4y = 0; y1 = e2x

Respuesta :

Answer:

[tex]\therefore y_2(x)=-\frac{e^{-6x}}{8}[/tex]

The general solution is

[tex]y=c_1e^{2x}-c_2.\frac{e^{-6x}}{8}[/tex]

Step-by-step explanation:

Given differential equation is

y''-4y'+4y=0

and [tex]y_1(x)=e^{2x}[/tex]

To find the [tex]y_2(x)[/tex] we are applying the following formula,

[tex]y_2(x)=y_1(x)\int \frac{e^{-\int P(x) dx}}{y_1^2(x)} \ dx[/tex]

The general form of equation is

y''+P(x)y'+Q(x)y=0

Comparing the general form of the differential equation to the given differential equation,

So, P(x)= - 4

[tex]\therefore y_2(x)=e^{2x}\int \frac{e^{-\int 4dx}}{(e^{2x})^2}dx[/tex]

           [tex]=e^{2x}\int \frac{e^{-4x}}{e^{4x}}dx[/tex]

           [tex]=e^{2x}\int e^{-4x-4x} \ dx[/tex]

            [tex]=e^{2x}\int e^{-8x} \ dx[/tex]

            [tex]=e^{2x}. \frac{e^{-8x}}{-8}[/tex]

           [tex]=-\frac{e^{-6x}}{8}[/tex]

[tex]\therefore y_2(x)=-\frac{e^{-6x}}{8}[/tex]

The general solution is

[tex]y=c_1e^{2x}-c_2.\frac{e^{-6x}}{8}[/tex]