we have that
y=-1/3(x+2)²+5
using a graph tool
see the attached figure
we know that
1) the graph open downward
2) the vertex of the graphic is the point (-2,5)
3) the axis of symmetry of the graph is x=-2
4) the x intercept values are (-5.873,0) and (1.873,0)
5) the y intercept value is (0,3.667)