Why write $\mathrm dx, \mathrm dt$ etc. at the beginning of an integral?
31979
Notation: Why write the differential first?
42992
How do I integrate the following? $\int{\frac{(1+x^{2})\mathrm dx}{(1-x^{2})\sqrt{1+x^{4}}}}$
112551
Demystify integration of $\int \frac{1}{x} \mathrm dx$
109192
Intuitive reason why $ \frac1j > \int_{j}^{j+1} \frac1x dx $ for $j$ < $x$
100866
Why is $\int_{0}^{\infty} \frac {\ln x}{1+x^2} \mathrm{d}x =0$?
45803
Integral of Derivative squared
125883
Moment of inertia: why $\mathrm{dI}=r^2\mathrm{dm}$ instead of $\mathrm{dI}=m\mathrm{dr^2}$?
123940
How can one prove the impossibility of writing $ \int e^{x^{2}} \, \mathrm{d}{x} $ in terms of elementary functions?
81057
Evaluation of $\int_{\frac{1}{e}}^{\tan x}\frac{t}{1+t^2}dt+\int_{\frac{1}{e}}^{\cot x}\frac{1}{t(1+t^2)}dt$
102902
Why does the interval where the differential equation makes sense not include $x = 0$?
142821
Why?$\int_0^1\int_{u(t)}^{u(t)+w(t)} f(t,v(t)) dv dt = \int_0^1 f(t,u(t)+\theta w(t))w(t) dt; ~~\theta\in[0,1] $
18732
How do I evaluate $\int \frac{\mathrm{d}x}{e^x + 1} $?
40830
Meaning of $\int\mathop{}\!\mathrm{d}^4x$
151127
Confirm that $\int_{0}^{\infty}t^{-1}\sin t dt=\pi/2$
72351
Applying integral substitution rule to $ \int \frac{mx+n}{ax+b} \mathrm{d}x$
41372
Stuck on crucial step while computing $\int_{- \infty}^{\infty} e^{-t^2}dt$
146353
Is there a way to rewrite integrals in Mathematica using u substitution?