Difference between $...$ and $$...$$ and the problem of equation centring
In usual LaTeX $...$ is used for writing in-line formulae and $$...$$ is reserved for formulae that reside on a separate line. The latter are normally centred by default. I am not sure I can understand how it works in Zettlr. Take a look at the screen-shot (each line with formula corresponds to the equation below). I would expect the first equation to be centred. Is there a way to make it so? Please give me your advice.