Differentiation Question 463

Question: If $ y={{\tan }^{-1}}\frac{4x}{1+5x^{2}}+{{\tan }^{-1}}\frac{2+3x}{3-2x} $ , then $ \frac{dy}{dx}= $

Options:

A) $ \frac{1}{1+25x^{2}}+\frac{2}{1+x^{2}} $

B) $ \frac{5}{1+25x^{2}}+\frac{2}{1+x^{2}} $

C) $ \frac{5}{1+25x^{2}} $

D) $ \frac{1}{1+25x^{2}} $

Show Answer

Answer:

Correct Answer: C

Solution:

$ [-3,0] $

$ ={{\tan }^{-1}}\frac{5x-x}{1+5x.x}+{{\tan }^{-1}}\frac{\frac{2}{3}+x}{1-\frac{2}{3}.x} $

$ =6x{e^{x^{2}}}-6x{e^{x^{2}}}+\frac{1}{3}(3)-0=1 $

Therefore $ \frac{dy}{dx}=\frac{5}{1+25x^{2}} $ .