4-2.Quadratic Equations and Inequations
hard

સમીકરણ $e^{\sin x}-2 e^{-\sin x}=2$ ના ઉકેલોની સંખ્યા મેળવો.

A

$2$

B

more than $2$

C

$1$

D

$0$

(JEE MAIN-2024)

Solution

Take $e^{\sin x}=t(t>0)$

$\Rightarrow \mathrm{t}-\frac{2}{\mathrm{t}}=2$

$\Rightarrow \frac{\mathrm{t}^2-2}{\mathrm{t}}=2$

$\Rightarrow \mathrm{t}^2-2 \mathrm{t}-2=0$

$\Rightarrow \mathrm{t}^2-2 \mathrm{t}+1=3$

$\Rightarrow(\mathrm{t}-1)^2=3$

$\Rightarrow \mathrm{t}=1 \pm \sqrt{3}$

$\Rightarrow \mathrm{t}=1 \pm 1.73$

$\Rightarrow \mathrm{t}=2.73 \text { or }-0.73(\text { rejected as } \mathrm{t}>0)$

$\Rightarrow \mathrm{e}^{\sin \mathrm{x}}=2.73$

$\Rightarrow \log _{\mathrm{e}} \mathrm{e}^{\sin \mathrm{x}}=\log _{\mathrm{e}} 2.73$

$\Rightarrow \sin \mathrm{x}=\log _{\mathrm{e}} 2.73>1$

So no solution.

Standard 11
Mathematics

Similar Questions

Start a Free Trial Now

Confusing about what to choose? Our team will schedule a demo shortly.