Practicing Success

Target Exam

CUET

Subject

-- Mathematics - Section B1

Chapter

Continuity and Differentiability

Question:

If $x=e^{y+e^{y+e^{y+... ~to ~\infty}}}, x > 0$, then $\frac{dy}{dx}$, is

Options:

$\frac{1+x}{x}$

$\frac{1}{x}$

$\frac{1-x}{x}$

$\frac{x}{1+x}$

Correct Answer:

$\frac{1-x}{x}$

Explanation:

We have,

$x=e^{y+e^{y+e^{y+... ~to~\infty}}}$

$\Rightarrow x=e^{y+x}$

$\Rightarrow \log _e x=(y+x)$

$\Rightarrow \frac{1}{x}=\frac{d y}{d x}+1$               [Differentiating with respect to x]

$\Rightarrow \frac{d y}{d x}=\frac{1-x}{x}$