For the equation F(x) = ax² + bx + c we have:
- maximum value if a<0
- minimum value if a>0
F(x) = -3x² + 18x + 3 ⇒ a = -3, b = 18
a < 0 ⇒ the function has a maximum value
Quadratic function has the maximum value (or minimum) at vertex of its parabola.
The maximum value is k at x=h where: and k = F(h)
Therefore:
<h3> The function has a maximum value of 30 at x = 3</h3>