MCQ
Let a curve $y=f(x)$ pass through the point $\left(2,\left(\log _{e} 2\right)^{2}\right)$ and have slope $\frac{2 y}{x \log _{e} x}$ for all positive real value of $x$. Then the value of $f(e)$ is equal to $.....$
  • $1$
  • B
    $2$
  • C
    $3$
  • D
    $4$

Answer

Correct option: A.
$1$
a
$y^{\prime}=\frac{2 y}{x \ell n x} \Rightarrow \frac{d y}{d x}=\frac{2 y}{x \ln x}$

$\Rightarrow \frac{d y}{y}=\frac{2 d x}{x \ell n x}$

$\Rightarrow \ell n|y|=2 \ell n|\ell n x|+C$

$\text { Put } x=2, y=(\ell n 2)^{2}$

$\Rightarrow \ln \left|(\ln 2)^{2}\right|=\ln \left|(\ln 2)^{2}\right|+c$

$\Rightarrow c=0$

$\Rightarrow y=(\text { en } x)^{2}$

$\Rightarrow f(e)=1$

Need a full question paper?

Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.

Start Generating Free