Question

What is the vertex of g(x) = –3x2 + 18x + 2?

Answer 1

$\bf \textit{vertex of a parabola}\\\\ \begin{array}{lccclll} g(x) = &-3x^2&+ 18x& + 2\\ &\uparrow &\uparrow &\uparrow \\ &a&b&c \end{array}\qquad \left(-\cfrac{{{ b}}}{2{{ a}}}\quad ,\quad {{ c}}-\cfrac{{{ b}}^2}{4{{ a}}}\right)$

Answer 2

The (x,y) point of the vertex is usually called (h,k)
"h" is calculated by the formula h = -b / (2*a)
h = -18 / (2 * -3)
h = 3

To get the "k" value, we input the value of "h" into the equation.
–3x2 + 18x + 2
"k" = -3*3*3 + 18*3 + 2
-27 + 54 + 2

"k" = 29

The vertex is (3, 29)

Source:
http://www.1728.org/quadr3.htm