% TeX root = ../main.tex
\begin{tikzpicture}[scale=0.5]
    \begin{axis}[
        axis lines = center,
        axis on top,
        xmin=-3.3,
        xmax=3.3,
        ymin=-3.3,
        ymax=3.3,
        y=1cm,
        x=1cm,
        ytick={-3,...,3},
        xtick={-3,...,3},
        xlabel = x,
        ylabel = y,
        font=\tiny
    ]
        \addplot [
            % domain=-3:3,
            name path = A,
            thick,
            % pattern=north east lines,
        ] {0.5*x + 1};
        \addplot[name path=C,draw=none] {3.3};

        \addplot[pattern=north west lines,pattern color=blue!30] fill between[of=A and C];
        \addplot[only marks,mark=o] coordinates {
                                                      (2,  2) (3,  2)
                                      (0,  1) (1,  1) (2,  1) (3,  1)
                    (-2, -0) (-1, -0) (0, -0) (1, -0) (2, -0) (3, -0)
            (-3,-1) (-2, -1) (-1, -1) (0, -1) (1, -1) (2, -1) (3, -1)
            (-3,-2) (-2, -2) (-1, -2) (0, -2) (1, -2) (2, -2) (3, -2)
            (-3,-3) (-2, -3) (-1, -3) (0, -3) (1, -3) (2, -3) (3, -3)

        };
        \addplot[only marks,mark=o,red!80] coordinates { (0, -2) };
    \end{axis} 
\end{tikzpicture}