\documentclass{article} %{standalone} 
\usepackage{tikz}
\begin{document}
\begin{tikzpicture}
\draw[<->] (-4,0) -- (4,0) node[right] {$x$};
\draw[<->] (0,-1.5) -- (0,1.5) node[above] {$y$};
\draw[scale=1, domain=-4:4, smooth,variable=\x,red] plot({\x},{sin(\x r)})node[right]{$y=\sin x$};
\draw[scale=1, domain=-4:4, smooth,variable=\x,blue] plot({\x},{cos(\x r)})node[above right]{$y=\cos x$};
\end{tikzpicture}
\end{document}
