The particular solution of the differential equation $\frac{dy}{dx}+\frac{3y}{x}= 0, y(1) = 1$ is |
$y=\frac{1}{x^3}$ $y=\frac{1}{x^2}$ $yx=\frac{1}{y}$ $yx=\frac{1}{y^2}$ |
$y=\frac{1}{x^3}$ |
The correct answer is Option (1) → $y=\frac{1}{x^3}$ Given: $\frac{dy}{dx} + \frac{3}{x} y = 0$, with $y(1) = 1$ This is a linear differential equation of the form $\frac{dy}{dx} + P(x)y = 0$ Integrating factor: $IF = e^{\int \frac{3}{x} dx} = e^{3 \ln x} = x^3$ Multiply both sides by $x^3$: $x^3 \frac{dy}{dx} + 3x^2 y = 0$ $\Rightarrow \frac{d}{dx}(x^3 y) = 0$ $\Rightarrow x^3 y = C$ Apply $y(1) = 1$: $1^3 \cdot 1 = C \Rightarrow C = 1$ |