Question 366865
Using the vertex form of a parabola, 
{{{y=a(x-h)^2 +k}}} where(h,k) is the vertex
f(x)=-2(x+1)^2 + 0
vertex (-1,0)
line of symmetry is x = -1


{{{drawing(300,300,-10,10,-10,10,blue(line(-1,10,-1,-10)),grid(1),graph( 300, 300,  -10, 10, -10, 10,-2(x+1)^2))}}}