Q51 / 155 · WBJEE 2022 · Mathematics
If $y=e^{\tan ^{-1} x}$ then
- Correct answerA$\left(1+x^2\right) y_2+(2 x-1) y_1=0$
- B$\left(1+x^2\right) y_2+2 x y=0$
- C$\left(1+x^2\right) y_2-y_1=0$
- D$\left(1+x^2\right) y_2+3 x y_1+4 y=0$
Solution
$\frac{d y}{d x}=e^{\tan ^{-1} x} \times \frac{1}{1+x^2}$
$\Rightarrow\left(1+x^2\right) y^{\prime}=y$
or $2 x y^{\prime}+\left(1+x^2\right) y^{\prime \prime}=y^{\prime}$
or $\left(1+x^2\right) y^{\prime \prime}+y^{\prime}(2 x-1)=0$
Hence, the correct answer is option: 'A'.