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Verify that y₁(x) = e^x solves the linear homogeneous differential equation shown below:

x y'' - (2x + 1) y' + (x + 1) y = 0
Then use Reduction of Order to find a second linearly independent solution, y₂(x), and hence the general solution. Use c₁ and c₂ to denote your constants.

User Luissquall
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Final answer:

To verify the solution y₁(x) = e^x, we substitute it into the differential equation and simplify. The result shows that e^x satisfies the equation. To find a second linearly independent solution, we use the Reduction of Order method. We assume y₂(x) = u(x) y₁(x) and solve for u(x), ultimately obtaining y₂(x) = rac{A e^3x}{2} + B e^2x as the second solution.

Step-by-step explanation:

In order to verify that y₁(x) = e^x solves the linear homogeneous differential equation, we will substitute y₁(x) into the differential equation and check if it satisfies the equation.

Step 1: Substitute y₁(x) = e^x into the differential equation:

x y'' - (2x + 1) y' + (x + 1) y = 0

x (d²/dx²(e^x)) - (2x + 1) (d/dx(e^x)) + (x + 1) (e^x) = 0

e^x + (2x + 1) e^x + (x + 1) e^x = 0

Now simplify the equation:

(e^x)(4x + 2) = 0

Since e^x is never equal to zero, the equation (e^x)(4x + 2) = 0 is satisfied when 4x + 2 = 0. Solving for x, we get x = -1/2.

Therefore, y₁(x) = e^x is a solution to the given differential equation.

To find a second linearly independent solution, we can use the method of Reduction of Order. Let's assume y₂(x) = u(x) y₁(x), where u(x) is a function to be determined. Substitute this into the differential equation:

x (u''(x)y₁(x) + 2u'(x)y₁'(x) + u(x)y₁''(x)) - (2x + 1) (u'(x)y₁(x) + u(x)y₁'(x)) + (x + 1) (u(x)y₁(x)) = 0

Expanding and simplifying the equation gives:

u''(x) + (2 - u'(x) - u(x)) e^x = 0

To find u(x), let's assume that u(x) = v(x)e^-x. Substitute this into the above equation:

v''(x) - 2v'(x) = 0

This is a simple linear equation that can be solved by integrating twice:

v'(x) = A e^2x

v(x) = rac{A e^2x}{2} + B

Therefore, u(x) = rac{A e^2x}{2} + B e^x

Finally, the second linearly independent solution y₂(x) is given by:

y₂(x) = u(x) y₁(x) = (rac{A e^2x}{2} + B e^x)e^x = rac{A e^3x}{2} + B e^2x

The general solution of the differential equation is then:

y(x) = c₁y₁(x) + c₂y₂(x) = c₁e^x + (c₂(rac{A e^3x}{2} + B e^2x))