1. **State the problem:** Solve the initial-value problem $$\frac{dy}{dx} = \frac{xy}{x+3}, \quad y(-2) = 3,$$ assuming $x > -3$.
2. **Rewrite the differential equation:** Separate variables to isolate $y$ and $x$ terms:
$$\frac{dy}{y} = \frac{x}{x+3} dx.$$
3. **Integrate both sides:**
$$\int \frac{1}{y} dy = \int \frac{x}{x+3} dx.$$
4. **Simplify the right integral:** Use polynomial division:
$$\frac{x}{x+3} = 1 - \frac{3}{x+3}.$$
5. **Rewrite the integral:**
$$\int \frac{x}{x+3} dx = \int \left(1 - \frac{3}{x+3}\right) dx = \int 1 dx - 3 \int \frac{1}{x+3} dx.$$
6. **Integrate:**
$$\int 1 dx = x,$$
$$\int \frac{1}{x+3} dx = \ln|x+3|.$$
7. **Combine results:**
$$\int \frac{x}{x+3} dx = x - 3 \ln|x+3| + C,$$
where $C$ is the constant of integration.
8. **Integrate left side:**
$$\int \frac{1}{y} dy = \ln|y|.$$
9. **Equate integrals:**
$$\ln|y| = x - 3 \ln|x+3| + C.$$
10. **Simplify using $x > -3$ assumption:** Since $x+3 > 0$, $|x+3| = x+3$.
11. **Exponentiate both sides:**
$$|y| = e^{x - 3 \ln(x+3) + C} = e^C e^x (x+3)^{-3}.$$
12. **Replace $e^C$ with $A$:**
$$y = A e^x (x+3)^{-3}.$$
13. **Use initial condition $y(-2) = 3$ to find $A$:**
$$3 = A e^{-2} (1)^{-3} = A e^{-2} \implies A = 3 e^{2}.$$
14. **Final solution:**
$$\boxed{y = 3 e^{2+x} (x+3)^{-3}}.$n
This is the exact formula for $y$ satisfying the initial-value problem with $x > -3$.
Separable Ode F5B7Cb
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