If for every positive number $\varepsilon$ there exists a positive number $\delta$, why not the other way back?
8842
What's wrong with this "backwards" definition of limit?
86866
Is there a number whose absolute value is negative?
148790
Basic question about proofs with the goal $\exists x P(x)$
8061
Why must the base of a logarithm be a positive real number not equal to 1?
49453
Why do I have to solve for $x$ in this proof, if I choose not to find a counterexample?
63950
Prove that to each $\epsilon >0$, there exists a $\delta >0$ so that the Lebesgue integral...
981
If $n^c\in\mathbb N$ for every $n\in\mathbb N$, then $c$ is a non-negative integer?
151493
Using $\epsilon$-$\delta$ to show a property of a function
51191
Does a negative number really exist?
109839
What is the Necessity of $...$ Around Numbers?
108917
Use $\delta-\epsilon$ to show that $\lim_{n\to\infty} a^{\frac{1}{n}} = 1$?
125821
Evaluating limits at positive and negative infinity
83204
Is every $G_\delta$ set the set of continuity points of some function $f$?
114043
Prove the existence of a real number satisfying a property
32524
Flawed proof that all positive integers are equal
3599
show that if ${a_n} \to a$, and $a>0$, then $\exists N$ such that $a_n>0$ for $n \ge N$.
16660
Prove that any positive number has an $n$th root