$dx=\frac {dx}{dt}dt $. Why is this equality true and what does it mean?
3360
Is $\frac{\textrm{d}y}{\textrm{d}x}$ not a ratio?
34790
Find $f(1)$ from equation $\int_{0}^{x}f(t)dt = x+\int_{x}^{1}tf(t)dt$
153794
What is the meaning of $1/(D+a)$, where $D$ is the derivative operator?
98271
Why does $(x \to a) ≠ (x = a)$ , But $f(x \to a) = f(x = a)$
125028
Prove the following equality using mathematical induction:
125883
Moment of inertia: why $\mathrm{dI}=r^2\mathrm{dm}$ instead of $\mathrm{dI}=m\mathrm{dr^2}$?
84413
Why is $\int_{-\infty}^\infty |g(x)|\,dx = \int_0^\infty \mu(\{x : |g(x)| \ge t\})\,dt$ true?
73099
Why is $d(x^2)= 2xdx$?
20280
Proving that expression is equivalent to the definition of derivative
104158
$\frac 00=$ ? Why It is un answerable?
1626
How do we prove $\int_I\int_x^1\frac{1}{t}f(t)\text{ dt}\text{ dx}=\int_If(x)\text{ dx}$
72278
What is the value of $\frac{\sin x}x$ at $x=0$?
100283
How to understand the notion of a differential of a function
114505
Initial value problem $t\frac{dx}{dt}=x+\sqrt{t^2+x^2}$
55888
Why my differential equations become True?
1002
Where is the flaw in this "proof" that 1=2? (Derivative of repeated addition)
76589
When does product of derivatives equals derivative of products?