We give a basic template for graphs in TikZ.
You do it like this:
\begin{image}
\begin{tikzpicture}
\begin{axis}[
xmin=-6.4,
xmax=6.4,
ymin=-1.2,
ymax=1.2,
axis lines=center,
xlabel=$x$,
ylabel=$y$,
every axis y label/.style={at=(current axis.above origin),anchor=south},
every axis x label/.style={at=(current axis.right of origin),anchor=west},
]
\addplot [ultra thick, penColor, smooth] {sin(deg(x))};
\end{axis}
\end{tikzpicture}
\end{image}
You can add more plots, like so:
\begin{image}
\begin{tikzpicture}
\begin{axis}[
xmin=-6.4,
xmax=6.4,
ymin=-1.2,
ymax=1.2,
axis lines=center,
xlabel=$x$,
ylabel=$y$,
every axis y label/.style={at=(current axis.above origin),anchor=south},
every axis x label/.style={at=(current axis.right of origin),anchor=west},
]
\addplot [ultra thick, penColor, smooth] {sin(deg(x))};
\addplot [ultra thick, penColor2, smooth,domain] {cos(deg(x))};
\addplot [ultra thick, penColor3, smooth] {1};
\addplot [ultra thick, penColor4, smooth] {-1};
\addplot [ultra thick, penColor5, smooth,domain=-1:1] {x};
\end{axis}
\end{tikzpicture}
\end{image}
You can make an array of plots like this: