More Latex Constructions
To make a set of equations one
above the other, use \begin{eqnarray} instead of \begin{equation}.
End each equation in the set with \\ (meaning end-of-line). If
you want the equations to line up nicely, indicate the character
that should be aligned in each equation with &. Here is an
example:
\begin{eqnarray}
x_0&=&\sin(a+b) \\
x_1&=&\cos(a+b)
\end{eqnarray}
Notice that the '=' signs will be lined up, and also notice that
you have to finish with \end{eqnarray}