(d^2-1)y=xsinx

3 min read Jul 03, 2024
(d^2-1)y=xsinx

Solving the Differential Equation (d^2-1)y=xsinx

In this article, we will explore the solution to the differential equation (d^2-1)y=xsinx. This equation is a second-order linear ordinary differential equation with a non-homogeneous term. We will use the method of undetermined coefficients to find the general solution of this equation.

The Homogeneous Equation

First, let's consider the homogeneous equation associated with the given equation:

(d^2-1)y = 0

This is a second-order linear homogeneous differential equation with constant coefficients. The characteristic equation is:

r^2 - 1 = 0

Solving for r, we get:

r = ±1

Therefore, the general solution of the homogeneous equation is:

y_h = c1e^x + c2e^(-x)

where c1 and c2 are arbitrary constants.

The Particular Solution

Now, let's find the particular solution of the non-homogeneous equation. We will use the method of undetermined coefficients. Assume that the particular solution has the form:

y_p = Axcosx + Bxsinx

where A and B are constants to be determined.

Substituting this into the original equation, we get:

(d^2-1)(Axcosx + Bxsinx) = xsinx

Expanding and simplifying, we get:

(-A + B)xsinx + (A + B)xcosx = xsinx

Equating the coefficients of xsinx and xcosx, we get:

-A + B = 1 A + B = 0

Solving this system of equations, we get:

A = -1/2 B = 1/2

Therefore, the particular solution is:

y_p = (-1/2)xcosx + (1/2)xsinx

The General Solution

The general solution of the differential equation is the sum of the homogeneous solution and the particular solution:

y = y_h + y_p = c1e^x + c2e^(-x) - (1/2)xcosx + (1/2)xsinx

where c1 and c2 are arbitrary constants.

This is the general solution of the differential equation (d^2-1)y=xsinx.

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