Question 417370
  <pre><font face = "Tohoma" size = 4 color = "indigo"><b>
Hi
Using the vertex form of a parabola, {{{y=a(x-h)^2 +k}}} where(h,k) is the vertex
f(x) = 3x^2-18x+11    |completing the square to put into vertex form
f(x) = 3(x^2-6)+11
f(x) = 3[(x-3)^2 - 9]+11
f(x) = 3(x-3)^2 - 16   Vertex is Pt(3,-16), minimum at this Pt ( a>)
 Line of symmetry is x = 3
{{{drawing(300,300,  -30,30,-30,30, blue(line(3,30,3,-30)),   grid(1),
circle(3, -16,0.8),
graph( 300, 300, -30,30,-30,30, 3x^2-18x+11))}}}