Hi,
Note: the vertex form of a Parabola opening up(a>0) or down(a<0),
where(h,k) is the vertex and x = h is the Line of Symmetry
The standard form is
, where the focus is (h,k + p)
f(x)= -(x+1)^2+4
vertex- V(-1,4)
line of symmetry- 
x intercept- 0 = -(x+1)^2 + 4, x = -1 ± 2, x is -3,-1
y intercept-
