What is the convention: $\frac{1}{\sqrt{-1}}=-i $ or $i$?
3712
Why $\sqrt{-1 \cdot {-1}} \neq \sqrt{-1}^2$?
80004
Why is $1/i$ equal to $-i$?
97890
$\{1,1\}=\{1\}$, origin of this convention
67923
"num - 1" vs "num -= 1"
24391
$\arcsin$ written as $\sin^{-1}(x)$
77486
What is the value of $i^i$?
22397
Is 0.9999... equal to -1?
150624
Why does the square root of a square involve the plus-minus sign?
12217
What is so special about $\alpha=-1$ in the integral of $x^\alpha$?
68155
Explanation why $\frac{(x-1)!-(x-1)}x$ is always an integer for prime $x$
97952
Square root of 1 is (not) -1
78351
Why is $(2, 1+\sqrt{-5})$ not principal?
146770
Why is $\frac{1}{\frac{1}{0}}$ undefined?
44630
Is $\frac{1}{\sqrt{2}}$ a fraction or not?
34430
Why does $(\frac{p-1}{2}!)^2 = (-1)^{\frac{p+1}{2}}$ mod $p$?
116649
Value of: $ \frac {1} {\sqrt {4} + \sqrt {5}} + \frac {1} {\sqrt {5} + \sqrt {6}} + ... + \frac {1} {\sqrt {80} + \sqrt {81}}$
121052
Where is the mistake? $-1=(-1)^{2/2}=\left(\left (-1\right)\displaystyle ^2\right)^{1/2}=1^{1/2}=\sqrt 1=1$