Are infinitesimals, i.e. $dx = ...$, rigorous and correct notation?
3360
Is $\frac{\textrm{d}y}{\textrm{d}x}$ not a ratio?
100004
Differentiating $e^x$ from first principles using limits.
49984
Valid justification for algebraic manipulation of $\mathrm{d}y/\mathrm{d}x$?
116776
Opposite of "infinitesimal"
31845
When not to treat dy/dx as a fraction in single-variable calculus?
124121
Is this logic behind the derivative of $x^x$ a coincidence?
153794
What is the meaning of $1/(D+a)$, where $D$ is the derivative operator?
112783
Is it mathematically valid to separate variables in a differential equation?
20675
$L=\lim_{x\to\infty}(f(x)+f'(x))$ exists . Which of the following statements is\are correct?
25913
Is writing $dx^2$ same as writing $d(x^2)$ in calculus
143874
Limit of derivative is zero. Does it imply a limit for f(x)?
69746
Can we abuse notation and write equations in differential one-form?
89421
Does $\int_{1}^{\infty} g(x)\ dx$ imply $\lim\limits_{x\to \infty}g(x)=0$?
125821
Evaluating limits at positive and negative infinity
17211
Is it wrong to tell children that $1/0 =$ NaN is incorrect, and should be $∞$?
60953
How could we formalize the introduction of new notation?
35622
Is floating-point == ever OK?