Question 412473
  <pre><font size = 3 color = "indigo"><b>
Hi
T = -0.2x^2+12x+11  x is the # of days tickets have been on sale  
and T is the number of Tickets expected to be sold on that day.
|parabola opens downward and completing the square...(-.2(x-30)^2 + 191)
 tells us the Vertex is Pt(30,191)
For example: it is expected the most tickets will be sold on day 30.
{{{drawing(300,300,   -200,200,-200,200,blue(line(30,200,30,-200)),    grid(1),
circle(30,191,7),
graph( 300, 300,-200,200,-200,200, -0.2x^2+12x+11 ))}}}