# Crazy Calculus 7

Calculus Level 2

$y=\sqrt { x+\sqrt { x+\sqrt { x+\sqrt { x+\cdots }}}}$

For $$x>0$$ , define $$y$$ as above. What is $$\dfrac{dy}{dx}$$?

• $$P: \dfrac{1}{2y-1}$$
• $$Q: \dfrac{x}{x+2y}$$
• $$R: \dfrac { 1 }{ \sqrt { 1+4x } }$$
• $$S: \dfrac{y}{2x + y}$$
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