This site "Easy Copy MathJax" provides a collection of MathJax (LaTeX) commands for writing mathematical equations and allows you to easily copy them. While you can access the website from smartphones and tablets, viewing it at a width of 1280px provides the best readability.
All
$\checkmark$
Formula
$\infty$
$\div$
$\geqq$
$\Big\{$
$\in$
$\Rightarrow $
${}_n \mathrm{ P }_k$
$\sum$
$\log$
$\angle$
$\sin$
$i$
$\lim$
$\frac{dy}{dx}$
$\int$
$\vec{a}$
$\Big(\qquad\Big)$
$\LARGE\boxplus$
$\large\circlearrowleft$
Symbol
$\diagup$
$\rightarrow$
$\lceil \ \rfloor$
$\cdots$
$\bigcirc$
$\triangle$
$\Box$
$\ast$
$\heartsuit$
Text
$a \ b \quad c$
$\scriptsize{ a }\normalsize{ b }\huge{ c }$
$\mathscr{ ABC }$
$\hat{ a }$
$\ell$
$\alpha\beta\gamma$
$\color{blue}{abc}$
$\S$
$\TeX$