What's wrong in this proof of 1=2?
39908
Finding the error in this proof that 1=2
50655
Proof of $f^{-1}(B_{1}\setminus B_{2}) = f^{-1}(B_{1})\setminus f^{-1}(B_{2})$
78736
Check my proof that $(ab)^{-1} = b^{-1} a^{-1}$
146867
Combinatorial Proof Of A Number Theory Theorem--Confusion
34913
Why does basic algebra provide one value for $x$ when there should be two?
79274
$1=2$ | Continued fraction fallacy
23406
How do I convince someone that $1+1=2$ may not necessarily be true?
62982
Prove $2^b-1$ does not divide $2^a + 1$ for $a,b>2$
103501
Question about a normal equation proof
16774
If $x,y,z\in\mathbb R\setminus \{1\}$ and $xyz=1$, prove that $\frac{x^2}{(x-1)^2}+\frac{y^2}{(y-1)^2}+\frac{z^2}{(z-1)^2}\ge 1$.
80148
Prove $\gcd(a+b,a^2+b^2)$ is $1$ or $2$ if $\gcd(a,b) = 1$
158335
Why is this $0 = 1$ proof wrong?
104124
Prove or disprove: $A-(B-C) = (A-B)-C$
140086
Does $3-4+1$ equal $0$ or $-2$.. or maybe $2$?
67588
Why does $|e^{ix}|^2 = 1$?
73391
Prove that if $\gcd(a,b)=1$, then $\gcd(a^2,b^2)=1$
95145
Does $\exp(2ir\pi)$ equal $1$? What's wrong?