Target Exam

CUET

Subject

-- Mathematics - Section B1

Chapter

Differential Equations

Question:

The general solution of the equation $\frac{d y}{d x}=1+x y$ is :

Options:

$y=c e^{-\frac{x^2}{2}}$

$y=c e^{\frac{x^2}{2}}$

$y=(x+c) e^{-\frac{x^2}{2}}$

None of these

Correct Answer:

None of these

Explanation:

$\frac{d y}{d x}-x y=1 \Rightarrow P=-x, Q = 1$

I.F. $= e^{-\int x d x}=e^{-\frac{x^2}{2}}$

∴ Solution is $y . e^{\frac{-x^2}{2}}=\int e^{-\frac{x^2}{2}} . 1 . d x+c$

Hence (4) is the correct answer.