Find the vertex of the graph of the quadratic function.
-$f ( x ) = x ^ { 2 } + 6 x - 7$
A) $( 6,65 )$
B) $( - 3 , - 34 )$
C) $( 3,20 )$
D) $( - 3 , - 16 )$

Question

Quizplus · Accepted Answer

The vertex of a quadratic function $f(x) = ax^2 + bx + c$ is given by the formula $(-b/2a, f(-b/2a))$. For $f(x) = x^2 + 6x - 7$, $a = 1$ and $b = 6$. The x-coordinate of the vertex is $-6/(2*1) = -3$. Substituting $x = -3$ into the function gives $f(-3) = (-3)^2 + 6(-3) - 7 = -16$. Thus, the vertex is $(-3, -16)$.

Find the Vertex of the Graph of the Quadratic Function f(x)=x2+6x−7f ( x ) = x ^ { 2 } + 6 x - 7f(x)=x2+6x−7

Find the Vertex of the Graph of the Quadratic Function $f ( x ) = x ^ { 2 } + 6 x - 7$