If $xy = e^{(x-y)}$, then $\frac{dy}{dx}$ is equal to:
Answer & explanation
Correct answer: option 2
The correct answer is Option (2) → $\frac{e^{x-y}-y}{x+e^{x-y}}$
Given equation: $xy = e^{(x - y)}$
Differentiate both sides with respect to $x$:
$y + x\frac{dy}{dx} = e^{(x - y)}(1 - \frac{dy}{dx})$
Rearrange terms:
$y + x\frac{dy}{dx} = e^{(x - y)} - e^{(x - y)}\frac{dy}{dx}$
Combine $\frac{dy}{dx}$ terms:
$(x + e^{(x - y)})\frac{dy}{dx} = e^{(x - y)} - y$
Hence,
$\frac{dy}{dx} = \frac{e^{(x - y)} - y}{x + e^{(x - y)}}$
Final answer: $\frac{dy}{dx} = \frac{e^{(x - y)} - y}{x + e^{(x - y)}}$