How to write a widehat(^) symbol and plus-minus in LaTeX?

Question: How to write a widehat(^) plus-minus in \(\LaTeX\)?

Answer: It can be written as: $\widehat{fg}$

\[\widehat{fg}\]

Question: How to write plus-minus (\(\pm\)) in \(\LaTeX\)?

Answer: It can be written as: $\lim_{n \to \pm \infty}$

\[\lim_{n \to \pm \infty}\]