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13h
comment Find sequence of differentiable functions $f_n$ on $\mathbb{R}$ that converge uniformly, but $f'_n$ converges only pointwise
Rotate the picture in this post by $\frac{\pi}{4}$ and take the top half of the picture to make them functions: math.stackexchange.com/questions/12906/is-value-of-pi-4
15h
answered Prove Using Definition that the Sequence $\frac{n+1}{\sqrt{n}+2}$ Diverges to Infinity
2d
comment Checking a possible proof of Fermat's Last Theorem
$$z^{2p} - 4(xy)^{p} = (x^p+y^p)^2- 4(xy)^{p}= (x^p-y^p)^2$$ so your $c=x^p-y^p$ ;)
2d
answered Kernel of the deriative of a polynomial on $F[x]$
2d
answered If $\gcd(a,b) = 1,$ then why is the set of invertible elements of $\mathbb Z_{ab}$ isomorphic to that of $\mathbb Z_a\times \mathbb Z_b$?
2d
comment Why is $f(x) = x + \frac{1}{x}$ a mapping contraction?
@Stef For $x \neq y$ the inequality $d(f(x),f(y))\le Cd(x,y)$ for some $0 < C <1$ is equivalent to $d(f(x),f(y)) < Cd(x,y)$ for some $0 < C <1$... One implication is obvious, while the other can be obtained by making $C$ bigger.
2d
answered Why is $f(x) = x + \frac{1}{x}$ a mapping contraction?
2d
awarded  Nice Answer
Nov
22
answered Proof by Geometric Intuition may Fail!!
Nov
20
answered Finding a polynomial mod 5: What did they do here?
Nov
20
awarded  Good Answer
Nov
19
answered Questions about poles
Nov
19
comment Smallest possible triangle to contain a square
What if a side of the square is along EF in your picture? You don't have two triangles anymore... What if only one or two vertices are on the edges?
Nov
19
comment Smallest possible triangle to contain a square
But what if the square sits in a different way inside the triangle?
Nov
17
comment factorial as difference of powers: $\sum_{r=0}^{n}\binom{n}{r}(-1)^r(l-r)^n=n!$?
@r9m Ty, fixed.
Nov
17
revised factorial as difference of powers: $\sum_{r=0}^{n}\binom{n}{r}(-1)^r(l-r)^n=n!$?
edited body
Nov
16
answered Examples where it is easier to prove more than less
Nov
15
answered How to prove that the center of a group is not a maximal subgroup?
Nov
13
comment If $f$ is continuous on $[0,\infty)$ and not bounded above implies…
@k-dubs Yes it is, I picked $N+1$ to make sure that $f(x_n)$ is also increasing by $1$.
Nov
12
answered If $f$ is continuous on $[0,\infty)$ and not bounded above implies…