Basic LaTeX questions

Question

Two (hopefully quick) questions about LaTeX:

1. How do you number select functions? I'm working in a documentclass{article}, if that matters. I want to have certain functions numbered such as

   function1  
   function2 (1)  
   function3  
   function4 (2)
   

2. How do you make a sign to evaluate an integral? I know how to do brackets, but is it possible to only make one straight light to the right of the function with the bounds of integration? I can't figure out how to do that.

Answer 1

I did what you asked in LyX and exported to LaTex:

\begin{document}
\L{\begin{equation}

\int_{0}^{1}x^{2}=\left.\frac{1}{3}x^{3}\right|_{0}^{1}=\frac{1}{3}\end{equation}
}

\L{\[
a=b+c\]
}

\L{\begin{equation}
1+1=2\end{equation}
}
\end{document}

---

Edit: Oh, and while you didn't ask - check out Detexify, since you'll definitely need to look up symbols in the future :)

Answer 2

The answer to 1.

\begin{eqnarray}
function1  \nonumber \\
function2            \\
function3  \nonumber \\
function4 
\end{eqnarray}

The answer to 2.

$\left. \frac 12 \right|_1^2$

Answer 3

If you wish to add a note to a piece of text, such that it renders something like the following:

The fox[1] jumped over the fence
...

[1] A fox is a clever mythical creature

then you can use the \footnote{} command, like so:

The fox\footnote{A fox is a clever mythical creature} jumped over the fence

If you wish to number an equation so you can refer to it later in your text, such that it renders something like the following:

    f(x,y)=3π    (1)

is numbered 1.

then you can use the \equation{} environment with a \label:

\begin{equation}
\label{f}
f(x,y)=3\pi
\end{equation}
is numbered \ref{f}.

Lastly, as for integration:

\[\int \frac{sin(x)}{cos(x)}dx\]
from 0 to 1,
\[\left.\frac{sin(x)}{cos(x)}\right|_0^1\]