Multiple choice. $(2$pts each$)$ Circle the best answer for each one of the following. $($Answer choices will be shuffled $-$ so do not just memorize the letters$).$

$28.$ To find whether a function is decreasing on an interval from $a$ to $b,$ we need to:

A$.$ Find intervals where

B$.$ Find intervals where $f^{\text{'}}(x)0.$

C$.$ Find intervals where

D$.$ Find intervals where $f^{\text{'}\text{'}}(x)0.$

$29.$ A critical value is an $x-$value, $x=a,$ where

A$.f^{\text{'}}(a)dne$

B$.f^{\text{'}}(a)=0$

C$.a$ is in the domain

D$.$ Only A or B

E$.$ C with A or B only

F$.$ A with B or C only

$30.$ A vertical asymptote of $f(x)$ occurs

A$.$ Where $f(x)$ dne.

B$.$ Where $f(x)$ has a division by $0.$

C$.$ Where $f^{\text{'}}(x)$ dne.

D$.$ Where $f(x)$ is fully reduced and has a division by $0.$

$30.(4$pts$)$ Fill in the blanks: On the unit circle the $x-$coordinate represents the value of

for any angle with that terminal side, and the $y-$coordinate represents the value of