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Solve the given differential equation by undetermined coefficients. y⁽⁴⁾ + 2y'' + y = (x - 1)² y(x) = ___

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Answer:

The value of the differential equation is y(x) = (C₁ + C₂x)e^(-x).

Explanation:

To solve the given differential equation using the method of undetermined coefficients, we assume that the particular solution has the form:

y_p(x) = (Ax^2 + Bx + C)(x - 1)^2

where A, B, and C are constants to be determined.

First, let's find the derivatives of y_p(x):

y_p'(x) = 2Ax(x - 1)^2 + (Ax^2 + Bx + C)(2(x - 1))

y_p''(x) = 2A(x - 1)^2 + 4A(x - 1)(x) + 2(Ax^2 + Bx + C)

y_p'''(x) = -2A(x - 1) + 4A(x) + 4Ax - 4A + 2(Ax^2 + Bx + C)

y_p⁽⁴⁾(x) = 4A + 4A + 2Ax + 4A + 2A = 10A + 2Ax

Now, substitute these derivatives into the differential equation:

10A + 2Ax + 2(2A(x - 1)^2 + 4A(x - 1)(x) + 2(Ax^2 + Bx + C)) + (Ax^2 + Bx + C) = (x - 1)^2

Simplifying this equation, we get:

10A + 2Ax + 4A(x - 1)^2 + 8A(x - 1)(x) + 4(Ax^2 + Bx + C) + Ax^2 + Bx + C = (x - 1)^2

Now, equating the coefficients of like powers of x, we get the following system of equations:

10A + 4A = 0 (coefficient of x⁰)

2A - 8A + B = 0 (coefficient of x¹)

4A + B + C = 0 (coefficient of x²)

Solving this system of equations, we find:

A = 0

B = -2A = 0

C = -4A = 0

Therefore, the particular solution y_p(x) = 0.

To find the general solution, we need to find the complementary solution by solving the homogeneous equation:

y'' + 2y' + y = 0

The characteristic equation is:

r^2 + 2r + 1 = 0

The roots of the characteristic equation are r = -1 (double root).

Therefore, the complementary solution is:

y_c(x) = (C₁ + C₂x)e^(-x)

where C₁ and C₂ are constants.

The general solution is the sum of the particular and complementary solutions:

y(x) = y_c(x) + y_p(x)

= (C₁ + C₂x)e^(-x)

Therefore, y(x) = (C₁ + C₂x)e^(-x).

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