$\frac{1}{\sqrt{-1}}=\sqrt{-1}$?
3712
Why $\sqrt{-1 \cdot {-1}} \neq \sqrt{-1}^2$?
14633
What's the thing with $\sqrt{-1} = i$
114861
equation $\frac{\frac{1}{x^2}-\frac{1}{y^2}}{\frac{1}{x^2}+\frac{1}{y^2}}$
158862
Show that $a(-1) = (-1)a = -a $.
60261
Is $\sqrt{x^2}=|x|$ or $=x$? Isn't $(x^2)^\frac12=x?$
64941
Why is $1 - \frac{1}{1 - \frac{1}{1 - \ldots}}$ not real?
126484
Why is $\Gamma\left(\frac{1}{2}\right)=\sqrt{\pi}$?
113334
If $x+\frac{1}{x}=\frac{1+\sqrt{5}}{2}$ then $x^{2000}+\frac{1}{x^{2000}}= $?
110826
prove that : $ i = \sqrt {-1}\ $
138256
What's the difference between $\mathbb{Q}[\sqrt{-d}]$ and $\mathbb{Q}(\sqrt{-d})$?
146770
Why is $\frac{1}{\frac{1}{0}}$ undefined?
17542
Why is $\sqrt{-x}*\sqrt{-x}=-x?$
102019
How to solve inequality $1-\frac{1}{x}\geq 0$ correctly?
129394
understanding $\frac{\partial x}{\partial y}\frac{\partial y}{\partial z}\frac{\partial z}{\partial x}=-1$
117691
Taylor series $\frac{z^2+z}{(z-1)^2}$ at $z=-1$
123436
Precise definition of limits and $\lim_{x\to-1}\frac1{\sqrt{x^2+3}}=\frac12$
13363
Why does an argument similiar to 0.999...=1 show 999...=-1?