Competishun Header

Report Issue

JEE-Advanced 2025
PAPER -1 2025
Question
For all $x>0$, let $y_1(x), y_2(x)$, and $y_3(x)$ be the functions satisfying
$ \begin{array}{ll} \frac{d y_1}{d x}-(\sin x)^2 y_1=0, & y_1(1)=5 \\ \frac{d y_2}{d x}-(\cos x)^2 y_2=0, & y_2(1)=\frac{1}{3} \\ \frac{d y_3}{d x}-\left(\frac{2-x^3}{x^3}\right) y_3=0, & y_3(1)=\frac{3}{5 e} \end{array} $
respectively. Then $\lim _{x \rightarrow 0^{+}} \frac{y_1(x) y_2(x) y_3(x)+2 x}{e^{3 x} \sin x}$ is equal to $\_\_\_\_$ i
Write Your Answer
✓ Correct! Well done.
✗ Incorrect. Try again or view the solution.
Solution
$ \begin{aligned} & \frac{d y_1}{d x}-\left(\sin ^2 x\right) y_1=0 \\ & \Rightarrow \int \frac{d y_1}{y_1}=\int \sin ^2 x d x \\ & \Rightarrow \int \frac{d y_1}{y_1}=\int \frac{1-\cos 2 x}{2} d x \\ & \Rightarrow \ln \left|y_1\right|=\frac{1}{2}\left(x-\frac{\sin 2 x}{2}\right)+C_1 \\ & \Rightarrow y_1=e^{\frac{1}{2}}\left(x-\frac{\sin 2 x}{2}\right)+C_1 \\ & \because y_1(1)=5 \\ & \Rightarrow C_1=\ln 5-\frac{1}{2}+\frac{\sin 2}{4} \\ & \Rightarrow y_1=e^{\frac{1}{2}}\left(x-\frac{\sin 2 x}{2}\right)+\ln 5-\frac{1}{2}+\frac{\sin 2}{4} \ldots \text { (i) } \\ & \text { and } \frac{d y_2}{d x}=\left(\cos ^2 x\right) y_2 \\ & \Rightarrow \int \frac{d y_2}{y_2}=\int \cos ^2 x d x=\int \frac{1+\cos 2 x}{2} d x \\ & \Rightarrow \ln \left|y_2\right|=\frac{1}{2}\left(x+\frac{\sin 2 x}{2}\right)+C_2 \end{aligned} $
$ \begin{aligned} & \because y_2(1)=\frac{1}{3} \\ & \Rightarrow C_2=-\ln 3-\frac{1}{2}-\frac{\sin 2}{4} \\ & \Rightarrow y_2=e^{\frac{1}{2}\left(x+\frac{\sin 2 x}{2}\right)-\ln 3-\frac{1}{2}-\frac{\sin 2}{4}} \text { …(2) } \\ & \text { and } \frac{d y_3}{d x}=\left(\frac{2-x^3}{x^3}\right) y_3 \\ & \Rightarrow \int \frac{d y_3}{y_3}=\int\left(\frac{2}{x^3}-1\right) d x \\ & \Rightarrow \ln \left|y_3\right|=-\frac{1}{x^2}-x+C_3 \\ & \because y_3(1)=\frac{3}{5 e} \end{aligned} $
$ \begin{aligned} & \Rightarrow C_3=1+\ln 3-\ln 5 \\ & \Rightarrow y_3=e^{\frac{1}{x^2}-x+1+\ln 3-\ln 5} \text { ...(3) } \end{aligned} $
From eq ${ }^n(1)$, (2) and (3)
$ \begin{aligned} & y_1(x) y_2(x) y_3(x)=e^{-\frac{1}{x^2}} \\ & \therefore \lim _{x \rightarrow 0^{+}} \frac{y_1(x) y_2(x) y_3(x)+2 x}{e^{3 x} \sin x} \\ & =\lim _{x \rightarrow 0^{+}} \frac{e^{\frac{-1}{x^2}}+2 x}{e^{3 x} \sin x} \\ & =\lim _{x \rightarrow 0^{+}} \frac{\frac{1}{x} e^{\frac{-1}{x^2}}+2}{e^{3 x}\left(\frac{\sin x}{x}\right)} \\ & =\frac{0+2}{1 \times 1}=2 \end{aligned} $
Question Tags
JEE Advance
Mathematics
Easy
Start Preparing for JEE with Competishun
Video Solution
BY competishun
Video Solution
Watch Solution
Filters 0
JEE Main
JEE Advance
Easy
Medium
Hard
Showing 18 questions
Q JEE MAIN 20262026
Given below are two statements
Statement I: $\mathrm{H}_2 \mathrm{O}$ molecules move from the chamber 1 to chamber 2 .
Statement II:...
JEE MainChemistryMedium
View Solution→
QJEE MAIN 20212021
Which of the following molecules does not show stereo isomerism ?
JEE MainChemistryEasy
View Solution→
QJEE MAIN 2021 2021
Given below are two statements :
Statement-I : α and β forms of sulphur can change reversibly between themselves with...
JEE MainChemistryEasy
View Solution→
QJEE MAIN 20212021
Which one of the following statements is not true about enzymes ?
JEE MainChemistryEasy
View Solution→
Q JEE MAIN 20212021
The solubility product of $\mathrm{Pbl}_2$ is $8.0 \times 10^{-9}$. The solubility of lead iodide in 0.1 molar solution of lead...
JEE MainChemistryHard
View Solution→
QJEE MAIN 20222022
In Carius method of estimation of halogen. 0.45 g of an organic compound gave 0.36 g of AgBr. Find out...
JEE MainChemistryEasy
View Solution→
QJEE MAIN 20232023
The number of units, which are used to express concentration of solutions from the following is _______.
Mass percent,...
JEE MainChemistryEasy
View Solution→
QJEE MAIN 20222022
250 g solution of D-glucose in water contains 10.8% of carbon by weight. The molality of the solution is nearest...
JEE MainChemistryHard
View Solution→
QJEE MAIN 2019 2019
A compound ' $X$ ' on treatment with $\mathrm{Br}_2 / \mathrm{NaOH}$, provided $\mathrm{C}_3 \mathrm{H}_9 \mathrm{~N}$, which gives positive carbylamine test....
JEE MainChemistryMedium
View Solution→
QJEE MAIN 20232023
In the following reaction, 'A' is
JEE MainChemistryMedium
View Solution→
QJEE MAIN 20212021
Which one of the following reactions does not occur ?
JEE MainChemistryEasy
View Solution→
QJEE MAIN 2021 2021
The major products A and B formed in the following reaction sequence are :
JEE MainChemistryEasy
View Solution→
QJEE MAIN 2021 2021
Correct statement about the given chemical reaction is :
JEE MainChemistryEasy
View Solution→
QJEE MAIN 2021 2021
Carbylamine test is used to detect the presence of primary amino group in an organic compound. Which of the following...
JEE MainChemistryEasy
View Solution→
QJEE-MAIN 20202020
Three isomers A. B and C (mol. formula $\mathrm{C}_2 \mathrm{H}_7, \mathrm{~N}$ ) give the following results
JEE MainChemistryEasy
View Solution→
QJEE MAIN 20212021
In the chemical reactions given above A and B respectively are :
JEE MainChemistryEasy
View Solution→
QJEE MAIN 2019 2019
Benzene diazonium chloride on reaction with aniline in the presence of dilute hydrochloric acid gives :
JEE MainChemistryEasy
View Solution→
QJEE MAIN 20222022
Stability of $\alpha$ - Helix structure of proteins depends upon
JEE MainChemistryEasy
View Solution→