Differentiation Question 7

Question: If $ y=x^{2}+\frac{1}{x^{2}+\frac{1}{x^{2}+\frac{1}{x^{2}+……\infty }}}, $ then $ \frac{dy}{dx}= $

Options:

A) $ \frac{2xy}{2y-x^{2}} $

B) $ \frac{xy}{y+x^{2}} $

C) $ \frac{xy}{y-x^{2}} $

D) $ \frac{2xy}{2+\frac{x^{2}}{y}} $

Show Answer

Answer:

Correct Answer: A

Solution:

$ y=x^{2}+\frac{1}{y}\Rightarrow y^{2}=x^{2}y+1 $

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

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