Answer :

naǫ
[tex](-6,20) \\ x=-6 \\ y=20 \\ \Downarrow \\ 20 \stackrel{?}{=} (-6)^2+2 \times (-6)-4 \\ 20 \stackrel{?}{=} 36-12-4 \\ 20 \stackrel{?}{=} 20 \\ 20 = 20 \\ \hbox{the point is on the graph}[/tex]

[tex](-4,4) \\ x=-4 \\ y=4 \\ \Downarrow \\ 4 \stackrel{?}{=} (-4)^2+2 \times (-4)-4 \\ 4 \stackrel{?}{=} 16-8-4 \\ 4 \stackrel{?}{=} 4 \\ 4 = 4 \\ \hbox{the point is on the graph}[/tex]

Both points are on the graph.