Differential Equations Question 98

Question: $ y=\frac{x}{x+1} $ is a solution of the differential equation

Options:

A) $ y^{2}\frac{dy}{dx}=x^{2} $

B) $ x^{2}\frac{dy}{dx}=y^{2} $

C) $ y\frac{dy}{dx}=x $

D) $ x\frac{dy}{dx}=y $

Show Answer

Answer:

Correct Answer: B

Solution:

$ y=\frac{x}{x+1}\Rightarrow \frac{1}{y}=1+\frac{1}{x} $

$ -\frac{1}{y^{2}}\frac{dy}{dx}=0-\frac{1}{x^{2}} $

Therefore $ x^{2}\frac{dy}{dx}=y^{2} $ .