InfiniteRepitition Difficult

Problem - 3861
Show that $$x+n=\sqrt{n^2 + x\sqrt{n^2+(x+n)\sqrt{n^2+(x+2n)\sqrt{\cdots}}}}$$

This equation is named after the Indian mathematician Srinivasa Ramanujan. It holds because \begin{align} & x + n \\ =\quad& \sqrt{(n+x)^2}\\ =\quad& \sqrt{n^2 + x (x + n + n)}\\ =\quad& \sqrt{n^2 + x\sqrt{(n+(x+n))^2}}\\ =\quad& \sqrt{n^2 + x\sqrt{n^2 + (x+n)(x+n + 2n)}}\\ =\quad& \sqrt{n^2 + x\sqrt{n^2 + (x+n)\sqrt{(n+(x+2n))^2}}}\\ =\quad& \cdots \end{align}

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