Q105 / 225 · JEE Main 2004 · Mathematics
If $x=e^{y+e^{y+. .10 \infty}}, x>0$, then $\frac{d y}{d x}$ is
- A$\frac{\mathrm{x}}{1+\mathrm{x}}$
- B$\frac{1}{x}$
- Correct answerC$\frac{1-x}{x}$
- D$\frac{1+x}{x}$
Solution
$x=e^{y+e^{y+e^{y+\ldots \ldots \infty}}} \Rightarrow x=e^{y+x}$
$\Rightarrow \ln x-x=y \Rightarrow \frac{d y}{d x}=\frac{1}{x}-1=\frac{1-x}{x}$
Hence, the correct answer is option: 'C'.