\begin{tikzpicture}[scale=.8]
             \draw[thin] (0,3)-- (0,0) -- (4,0) node[right] {\(x\)};
             \draw[thin] (0,0)--(-1.9,-1.3) node[below left]{\(y\)};
             \draw[thin] (-.1,3) node[left]{\(z\)};
            \draw[dashed] (0,0) -- (3.3,-0.7);
             \draw[->] (0,2) -- (0.55,1.55);
             \draw (.55,1.55)--(3.3,-0.7);
             \draw[color=blue] (0,0) circle (2cm) (-2,0) arc (180:360:2cm and .4cm);
             \draw[color=blue,dashed] (2,0) arc (0:180:2cm and .4cm);
             \tkzDefPoint(0,2){N}
             \tkzDefPoint(1.1,1.1){P}
             \tkzDefPoint(3.3,-.7){imP}
             \tkzDrawPoints[fill=red](N,P,imP)
             \tkzLabelPoint[above right=-1pt](N){\(N\)};
             \tkzLabelPoint[above right=-2pt](P){\(P=(a,b,c)\)};
             \tkzLabelPoint[right=-1pt](imP){\(\phi(P)\)};\end{tikzpicture}