What software do you use to write limits,integrals,sequences,etc?

Question

I tried using office word and I couldn't copy paste my limits,sequences and I want help.Does anyone know what program can write the functions in bold as you do?I am new in this and I have no idea what to use.I'm asking for guidance.I am so sorry that I had to write my functions as normal texts but I don't know how to write them in bold as you do.

Answer 1

We don't write in bold. We typeset in $\LaTeX$, which is (and has been for many years) the best way to typeset mathematics (and a lot of things, when you know the right packages for the task).