Practicing Success

Target Exam

CUET

Subject

-- Mathematics - Section B1

Chapter

Continuity and Differentiability

Question:
What is $\frac{dy}{dx}$ where $y=e^{e^{e^{x^2}}}$?
Options:
$e^{e^{e^{x^2}}}$
$e^{e^{e^{x^2}}}2x$
$e^{e^{e^{x^2}}}e^{e^{x^2}}e^{x^2}2x$
$e^{e^{e^{x^2}}}e^{x^2}$
Correct Answer:
$e^{e^{e^{x^2}}}e^{e^{x^2}}e^{x^2}2x$
Explanation:
Taking logarithm in both sides $\log y=e^{e^{x^2}}$. Taking log again we get $\log(\log y)=e^{x^2}$. Differentiating both sides w.r.to x we get $1/\log y\frac{d}{dx}(\log y)=\frac{d}{dx}(e^{x^2})$. So $\frac{1}{y\log y}\frac{dy}{dx}=e^{x^2}2x$. So$\frac{dy}{dx}=y\log ye^{x^2}2x=e^{e^{e^{x^2}}}e^{e^{x^2}}e^{x^2}2x$