Question 815764
  <pre><font face = "Tohoma" size = 3 color = "indigo"><b> 
Hi,
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  
f(x)= 3x^2 + 6x +4
    = 3(x+1)^2 - 3 + 4  |Completing the Square
    = 3(x+1)^2 +1  V(-1,1), a= 3 >0 opening Up, f(x) = 1 is a minimum
{{{drawing(300,300,   -10,10,-10,10,  
 grid(1),
circle(-1, 1,0.4),
graph( 300, 300, -10,10,-10,10,0,3x^2 + 6x +4))}}}