Find the general solution of the given differential equation. x2y’ + x(x + 2)y = ex
Solution:
The given differential equation is
x2y’ + x(x + 2)y = ex
Let us multiply be ex on both sides
x2exy’ + (x2 + 2x)exy = e2x
We know that
(x2ex)’ = 2xex + x2ex = (x2 + 2x)ex
Let us collapse the LHS and write it as the derivative of the product.
(x2exy)’ = e2x
\(\\x^{2}e^{x}y=\int e^{2x}dx \\ \\x^{2}e^{x}y=\frac{e^{2x}}{2}+C \\ \\y=\frac{e^{x}}{2x^{2}}+\frac{C}{x^{2}e^{x}}\)
Depending on the initial value (0, ∞) or (-∞, 0) would be the largest interval.
When x → ∞ \(\frac{C}{x^{2}e^{x}}\) term approaches zero, so it is the only transient term.
Therefore, the general solution is \(y=\frac{e^{x}}{2x^{2}}+\frac{C}{x^{2}e^{x}}\).
Find the general solution of the given differential equation. x2y’ + x(x + 2)y = ex
Summary:
The general solution of the given differential equation x2y’ + x(x + 2)y = ex is \(y=\frac{e^{x}}{2x^{2}}+\frac{C}{x^{2}e^{x}}\).
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