Use the graph shown, sketched on $0,7,$ for Questions $54\mathrm{.}76$

$54.$ From the graph it follows that

$($A$)f$ is discontinuous at $x=4$

$($B$)f$ is decreasing for $ffx=0fx=7fx=5ffff(0,4)(4,5)(5,7)(4,7)0$

$(D)f$ has a local maximum $atx=0$

$(E)f$ has a local minimum $atx=7$

$55.$ Which statement best describes $fatx=5?$

$(A)f$ has a root.

$(B)f$ has a maximum.

$(C)f$ has a minimum.

$(D)f$ has a point $of$ inflection.

$(E)$ none $of$ these

The function $is$ concave downward for which interval?

$(A)(0,4)$

$(B)(4,5)$

$(C)(5,7)$

$(D)(4,7)$

$(E)$ none $of$ these$4$

$(C)fis$ constant for $0$

$(D)f$ has a local maximum $atx=0$

$(E)f$ has a local minimum $atx=7$

$55.$ Which statement best describes $fatx=5?$

$(A)f$ has a root.

$(B)f$ has a maximum.

$(C)f$ has a minimum.

$(D)f$ has a point $of$ inflection.

$(E)$ none $of$ these

The function $is$ concave downward for which interval?

$(A)(0,4)$

$(B)(4,5)$

$(C)(5,7)$

$(D)(4,7)$

$(E)$ none $of$ these