Practicing Success

Target Exam

CUET

Subject

-- Mathematics - Section B1

Chapter

Continuity and Differentiability

Question:

Let $y=\sqrt{\sin x+\sqrt{\sin x+\sqrt{\sin x+.....}}}$, then $\frac{dy}{dx}$ is:

Options:

$\frac{2y}{\cos x}$

$\frac{\cos x}{2y-1}$

$\frac{2y-1}{2y+1}$

$\frac{\cos x}{2y+1}$

Correct Answer:

$\frac{\cos x}{2y-1}$

Explanation:

$y=\sqrt{\sin x+\sqrt{\sin x+\sqrt{\sin x+.....}}}=\sqrt{\sin x+y}$

$⇒y^2=\sin x+y⇒2y\frac{dy}{dx}=\cos x+\frac{dy}{dx}$

$⇒\frac{dy}{dx}=\frac{\cos x}{2y-1}$