Why is $ {\sqrt 4} \times {\sqrt 4} = 4$ And not -4?
53958
General misconception about $\sqrt x$
153043
Show that $\sqrt{4+2\sqrt{3}}-\sqrt{3}$ is rational using the rational zeros theorem
78351
Why is $(2, 1+\sqrt{-5})$ not principal?
59818
Why $(-2)^{2.5}$ isn't equal to $((-2)^{25})^{1/10}$?
26069
Why is $X^4-16X^2+4$ irreducible in $\mathbb{Q}[X]$?
157868
Is it wrong to say $ \sqrt{x} \times \sqrt{x} =\pm x,\forall x \in \mathbb{R}$?
63679
Picture/intuitive proof of $\cos(3 \theta) = 4 \cos^3(\theta)-3\cos(\theta)$?
137285
Prove $\mathbb{Z}_2 \times \mathbb{Z}_2$ is not isomorphic to $\mathbb{Z}_4$
81875
why is $\sqrt{-1} = i$ and not $\pm i$?
73277
Prove $[\sqrt{x}+\sqrt{x+1}]=[\sqrt{4x+2}], x \in \Bbb N$
58284
How to prove that $\sqrt[3] 2 + \sqrt[3] 4$ is irrational?
66364
Why is $(\sqrt{2}+\sqrt{3})^{2008}$ so close to an integer?
103223
If $x^a$ is $x$ multiplied $a$ times, then how does $x^{-1}$ make sense?
107390
Why is (-1)(-1) = 1?
150624
Why does the square root of a square involve the plus-minus sign?
110826
prove that : $ i = \sqrt {-1}\ $
150152
If $|x -4 | + |y - 4| =4$ then how many integers value the sets (x,y) have?