# When are two answers too similar?

Is it true that $0.999999999\ldots = 1$? math fallacy problem: $-1= (-1)^3 = (-1)^{6/2} = \sqrt{(-1)^6}= 1$? Why $\sqrt{-1 \times -1} \neq \sqrt{-1}^2$? have many similar answers. When is this sanctioned?

Because I like figures, I wrote https://math.stackexchange.com/a/676192/85079 by dint of another answer. I referred to it. I think this similar but not identical answer can aid other people. But a moderator deleted it. The changes can aid other people, ergo can we have both? Thanks to all.

It's fine (and perhaps unavoidable) that $2$ users submit structurally similar answers by happenstance. But this does not imply that copy-pasting someone else's answer and changing a few symbols should be tolerated.
• @Asaf: $\textbf{colo}\color{red}{\textbf{u}}\textbf{rs}$. – user642796 Mar 8 '14 at 8:04