19. You put a yam in the oven. After 45 minutes, you take it out. Let [tex]$f(t)$[/tex] be the temperature of the yam in degrees Fahrenheit, where [tex]$t$[/tex] is the number of minutes after you placed it in the oven. Explain the meaning of the following statements in everyday language:

a. [tex]$f(0)=65$[/tex]
- The initial temperature of the yam when it was placed in the oven was 65°F.

b. [tex]$f(5) < f(10)$[/tex]
- The temperature of the yam after 5 minutes in the oven is less than its temperature after 10 minutes.

c. [tex]$f(40)=f(45)$[/tex]
- The temperature of the yam remained constant between 40 and 45 minutes in the oven.

d. [tex]$f(45) > f(60)$[/tex]
- The temperature of the yam at 45 minutes (when it was taken out of the oven) is greater than its temperature at 60 minutes.

Sure, let's break down the meanings of the given statements one by one in everyday language:

a. [tex]$ f(0) = 65 $[/tex]
- This means that the initial temperature of the yam was 65 degrees when you first placed it in the oven.

b. [tex]$ f(5) < f(10) $[/tex]
- This means that the temperature of the yam at 5 minutes after it was placed in the oven is less than its temperature at 10 minutes. In other words, the yam is heating up, and it is hotter at 10 minutes than it was at 5 minutes.

c. [tex]$ f(40) = f(45) $[/tex]
- This means that the temperature of the yam at 40 minutes and at 45 minutes after it was placed in the oven is the same. This suggests that the yam has reached a steady temperature and is not heating up any further by the time it reaches 40 minutes.

d. [tex]$ f(45) > f(60) $[/tex]
- This means that the temperature of the yam at 45 minutes after it was placed in the oven is higher than its temperature at 60 minutes after it was placed in the oven. This indicates that after you took the yam out of the oven at 45 minutes, it started to cool down.

So overall, these statements describe the heating up and cooling down process of the yam in the oven over time.