Why isn't $(2x+x^2)^{1/2}$ the same as $(2x)^{1/2}+x$?
19
Why is the square root of a sum not equal to the square root of each its addends?
55175
Is the function $f(x) = x^2 - 2x$ one-to-one?
52461
Why does $(g^b \bmod m)^a \bmod m = (g^a \bmod m)^b \bmod m$?
1002
Where is the flaw in this "proof" that 1=2? (Derivative of repeated addition)
136602
Why is $\int_1^{\infty}(1/x^2)\,dx$  less than $\sum_{n=1}^{\infty} 1/(n^2)$?
39908
Finding the error in this proof that 1=2
10400
Why adding these two double does not give correct answer?
41204
Why do I get one extra wrong solution when solving $2-x=-\sqrt{x}$?
17265
Intuition for why equations of the form $k^x=x^c$ are not solvable trivially?
4178
Solve $f(x)f(2x^2) = f(2x^3+x)$
25913
Is writing $dx^2$ same as writing $d(x^2)$ in calculus
67678
When is "i += x" different from "i = i + x" in Python?
66364
Why is $(\sqrt{2}+\sqrt{3})^{2008}$ so close to an integer?
69299
Why do these two multiplication operations give different results?
67588
Why does $|e^{ix}|^2 = 1$?
95145
Does $\exp(2ir\pi)$ equal $1$? What's wrong?
60261
Is $\sqrt{x^2}=|x|$ or $=x$? Isn't $(x^2)^\frac12=x?$