Differentiation Question 260

Question: If $ y=\frac{e^{2x}+{e^{-2x}}}{e^{2x}-{e^{-2x}}} $ , then $ \frac{dy}{dx}= $

[AI CBSE 1988]

Options:

A) $ \frac{-8}{{{(e^{2x}-{e^{-2x}})}^{2}}} $

B) $ \frac{8}{{{(e^{2x}-{e^{-2x}})}^{2}}} $

C) $ \frac{-4}{{{(e^{2x}-{e^{-2x}})}^{2}}} $

D) $ \frac{4}{{{(e^{2x}-{e^{-2x}})}^{2}}} $

Show Answer

Answer:

Correct Answer: A

Solution:

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

$ \therefore \frac{dy}{dx}=\frac{(e^{2x}-{e^{-2x}})2(e^{2x}-{e^{-2x}})-(e^{2x}+{e^{-2x}})2(e^{2x}+{e^{-2x}})}{{{(e^{2x}-{e^{-2x}})}^{2}}} $

$ =\frac{-8}{{{(e^{2x}-{e^{-2x}})}^{2}}} $ .