Why don't $\sqrt{a*b}=\sqrt{a}*\sqrt{b}$ holds true when one of $a$ & $b$ is imaginary number?
3712
Why $\sqrt{-1 \cdot {-1}} \neq \sqrt{-1}^2$?
25623
Does $\sqrt{a+b} \le \sqrt a + \sqrt b$ hold for all positive real numbers a and b?
147986
Prove: if $|z|=1$ than $\frac{z+1}{z-1}$ is an imaginary number
68092
Does square difference prove that 1 = 2?
84626
Why in these matrices are $AB=BA$ not equal? What is the logic behind them?
8589
$\sqrt[b_1]{a_1}+\sqrt[b_2]{a_2}+\cdots+\sqrt[b_k]{a_k}$ not an integer
82097
If $A \succeq B$, is it true that $B^{-1} \succeq A^{-1}$?
14633
What's the thing with $\sqrt{-1} = i$
139934
In $\mathbb{Z}/(n)$, does $(a) = (b)$ imply that $a$ and $b$ are associates?
100549
If $e^A$ and $e^B$ commute, do $A$ and $B$ commute?
96554
Why is $x^0 = 1$ except when $x = 0$?
157087
Can anyone explain why $a^{b^c} = a^{(b^c)} \neq (a^b)^c = a^{(bc)}$
56745
Why does this not work with an imaginary exponent?
67588
Why does $|e^{ix}|^2 = 1$?
17707
Why is ${x^{\frac{1}{2}}}$ the same as $\sqrt x $?
58636
Do the real numbers and the complex numbers have the same cardinality?
131844
When does $(e^a)^b = e^{ab}$ hold?