Question 931856
f(x) = x2 + 2x - 9
f(x) = (x+1)^2 - 1 - 9
f(x) = (x+1)^2 - 10  Parabola opening Up a = 1> 0
V(-1,-10) min
.....
the vertex form of a Parabola opening up(a>0) or down(a<0), 
{{{y=a(x-h)^2 +k}}} 
where(h,k) is the vertex  and  x = h  is the Line of Symmetry