[tex]\bf \textit{vertex of a parabola}\\ \quad \\
\begin{array}{lccclll}
f(x)=&-16x^2&+22x&+3\\
&\uparrow &\uparrow &\uparrow \\
&a&b&c
\end{array}\qquad
\left(-\cfrac{{{ b}}}{2{{ a}}}\quad ,\quad {{ c}}-\cfrac{{{ b}}^2}{4{{ a}}}\right)[/tex]
if the leading term's coefficient is negative, is going down, if positive, is going up
this one is -16, thus the parabola opens downwards, meaning, goes up up up, reaches a U-turn, the vertex, then goes down down down
so, it reaches a "maximum" point at the vertex
