Question 636057
  <pre><font face = "Tohoma" size = 3 color = "indigo"><b> 
Hi,
Note: 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  

Assume you meant: 
{{{f(x)=3x^2-24x-3 = 3(x-4)^2 - 48 - 3 = 3(x-4)^2 -51}}}  
parabola opening Upward a = 3 > 0,    Vmin(4,-51)
a. Is f(4) a <u>minimum</u> or maximun
 b. What is the value?  -51
 c. The domain of f is?  x is any real number
 d. The range of f is?   f(x) > -51

{{{drawing(300,300,   -6, 20, -70, 50,  blue(line(4,50,4,-70))  , grid(1),
circle(4, -51,0.3),
graph( 300, 300, -6, 20, -70, 50,0,3x^2-24x-3  ))}}}