Q90 / 170 · Manipal (MET) 2017 · Mathematics
The solution of the equation $(2 y-1) d x-(2 x+3) d y=0$ is
- A$\frac{2 x-1}{2 y+3}=c$
- Correct answerB$\frac{2 x+3}{2 y-1}=c$
- C$\frac{2 x-1}{2 y-1}=c$
- D$\frac{2 y+1}{2 x-3}=c$
Solution
The given equation is
$(2 y-1) d x-(2 x+3) d y=0$
or it can be rewritten as
$\frac{d x}{(2 x+3)}-\frac{d y}{(2 y-1)}=0$
On integrating both sides, we get
$\begin{gathered}
\int \frac{1}{(2 x+3)} d x-\int \frac{1}{(2 y-1)} d y=0 \\
\Rightarrow \frac{1}{2} \log (2 x+3)-\frac{1}{2} \log (2 y-1)=\frac{1}{2} \log c \\
\Rightarrow \log \left(\frac{2 x+3}{2 y-1}\right)=\log c \Rightarrow \frac{2 x+3}{2 y-1}=c
\end{gathered}$
Hence, the correct answer is option: 'B'.