We know that the graph of:
[tex]y=-6x^2[/tex]
is a downward open parabola with vertex at (0,0)
and the graph of:
[tex]y=-6x^2+4[/tex]
is again a downward open parabola but the vertex of the parabola are at (0,4)
This means that the graph of the second function id obtained by applying a translation transformation that is a shift of the first function "4" units upward.