\documentclass{article}
\usepackage{tikz}
\begin{document}
\begin{tikzpicture}
\draw[<->] (-4,0) -- (4,0) node[right] {$x$};
\draw[<->] (0, -1,5) -- (0,1,5) node[above] {$x$};
\draw[scale=1 , domain=-4:4, smooth ,variable=\x ,red]
       plot({\x},{sin(\x)}) 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}

