When can I treat infinitesimals as numbers?
31845
When not to treat dy/dx as a fraction in single-variable calculus?
80060
Is $\frac{1}{\infty}$  equal zero?
75466
During U-substitution, is the $du$ that we use as the infinitesimal in $\int f(u) \ du$ changing size?
43283
More numbers between $[0,1]$ or $[1,\infty)$?
119982
how to express the set of natural numbers in ZFC
12547
Is it okay to "ignore" small numbers in limits where $x$ approaches infinity?
118175
Can we say that $\frac{0}{0}$ is every number?
50235
Numbering theorem-like environments
125821
Evaluating limits at positive and negative infinity
75791
What is the proper way to handle the limit with little-$o$?
19655
Why don't we define "imaginary" numbers for every "impossibility"?
70196
Is there any well-ordered uncountable set of real numbers under the original ordering?
151308
Is it possible to turn infinite sums into infinite products?
154225
How many positive numbers need to be added together to ensure that the sum is infinite?
112910
Is the set of real numbers really uncountably infinite?
46798
Is it possible that the zeroes of a polynomial form an infinite field?
157728
When can you interchange composition of a limit?