Is this a valid proof for $1+1=2$?
108873
How would one be able to prove mathematically that $1+1 = 2$?
61604
$V = V_1 + V_2$ confusion? Why is my "proof "incorrect?
19628
What is wrong with this fake proof $e^i = 1$?
108923
What is wrong with this false proof? $-1=(-1)^1=(-1)^\frac{2}{2}=((-1)^2)^\frac{1}{2}=\sqrt{(-1)^2}=\sqrt{1}=1$
100571
Prove $(1-a)(1-b)(1-c)(1-d)\geq abcd$ if $a^2+b^2+c^2+d^2=1$
147528
Where's the error in this $2=1$ fake proof?
33082
Proving $\sum_{i=0}^n 2^i=2^{n+1}-1$ by induction.
59006
Proof of $\gcd(n!+1, (n+1)!+1)=1$?
65511
Proving the following false: $f(x)=2x+1$ produces a prime number if and only if x is prime
36837
Prove $\frac{1+a^{2}}{1+b+c^{2}} +\frac{1+b^{2}}{1+c+a^{2}} +\frac{1+c^{2}}{1+a+b^{2}} \geq 2$
145466
Is this a valid mathematical proof?
2675
Proof $1+2+3+4+\cdots+n = \frac{n\times(n+1)}2$
45037
Show $(2^m-1,2^n+1)=1$ if $m$ is odd
10348
Prove that if the $\gcd(a,b)=1$, then $\gcd(a+b,ab)=1$
56315
Prove $\frac{|a+b|}{1+|a+b|}<\frac{|a|}{1+|a|}+\frac{|b|}{1+|b|}$.
13012
Why can a = b imply 2 = 1?
147986
Prove: if $|z|=1$ than $\frac{z+1}{z-1}$ is an imaginary number