Question

question 1
find the vertex of the following quadratic function:
$f(x) = 2x^2 - 2x - 12$
$\bigcirc$ $(2, -12)$
$\bigcirc$ $(0.5, -12.5)$
$\bigcirc$ $(12.5, 0.5)$
$\bigcirc$ $(-0.5, -10.5)$

Explanation:

Step1: Find x-coordinate of vertex

For quadratic $f(x)=ax^2+bx+c$, $x=-\frac{b}{2a}$. Here $a=2, b=-2$:
$x=-\frac{-2}{2\times2}=\frac{2}{4}=0.5$

Step2: Find y-coordinate of vertex

Substitute $x=0.5$ into $f(x)$:
$f(0.5)=2(0.5)^2-2(0.5)-12=2(0.25)-1-12=0.5-1-12=-12.5$

Answer:

B. (0.5, -12.5)