Question

match each expression with its value.
-6 -5 7 undefined
$f(4.999)$ $circ$ $circ$ $circ$ $circ$
$f(5)$ $circ$ $circ$ $circ$ $circ$
$f(5.0001)$ $circ$ $circ$ $circ$ $circ$
$f(9)$ $circ$ $circ$ $circ$ $circ$

Explanation:

Step1: Locate $x=4.999$ on graph

$x=4.999$ is just left of $x=5$, on the segment where $y=-6$.

Step2: Locate $x=5$ on graph

$x=5$ has an open circle at $y=-6$ and a closed circle at $y=7$; use the closed circle value $y=7$.

Step3: Locate $x=5.0001$ on graph

$x=5.0001$ is just right of $x=5$, on the segment where $y=-5$.

Step4: Locate $x=9$ on graph

$x=9$ is a closed circle on the top segment, where $y=7$.

Answer:

• $f(4.999)$: $\boldsymbol{-6}$
• $f(5)$: $\boldsymbol{7}$
• $f(5.0001)$: $\boldsymbol{-5}$
• $f(9)$: $\boldsymbol{7}$