A very basic question:
How to type mathematics correctly in this website? I am a new member.
TO briefly expand on Agusti's answer, $\LaTeX$ is used to represent math. You simply put the symbol $ in front of and after the math.
You can see the $\LaTeX$ crash course here. Just use dollar signs instead of their [tex] and [\tex] symbols. You can practice in their forums if you like. They have a button where you can preview $\LaTeX$.