The particular solution of the differential equation $\log(\frac{dy}{dx})=3x+4y$ satisfying $y = 0$ when $x = 0$ is: |
$3e^{3x}+4e^{-4y}+7=0$ $3e^{3x}-4e^{-4y}-7=0$ $4e^{3x}+3e^{-4y}-7=0$ $4e^{3x}-3e^{-4y}+7=0$ |
$4e^{3x}+3e^{-4y}-7=0$ |
The correct answer is Option (3) → $4e^{3x}+3e^{-4y}-7=0$ Given: \(\log\left(\frac{dy}{dx}\right) = 3x + 4y\) \(\frac{dy}{dx} = e^{3x+4y}\) \(e^{-4y} \frac{dy}{dx} = e^{3x}\) \(\frac{d}{dx}\left(-\frac{1}{4} e^{-4y}\right) = e^{3x}\) \(-\frac{1}{4} e^{-4y} = \frac{1}{3} e^{3x} + C\) Using \(y(0)=0\): \(-\frac14 e^{0} = \frac13 e^{0} + C\) $(-\frac14 = \frac13 + C$ $C = -\frac{7}{12})$ \(-\frac14 e^{-4y} = \frac13 e^{3x} - \frac{7}{12}\) \(e^{-4y} = -\frac43 e^{3x} + \frac73\) Particular solution: $4e^{3x}+3e^{-4y}-7=0$ |