Chapter 3.2, Problem 35E

a.

To determine

To determine the domain of the given function.

Answer to Problem 35E

  $55t=20g$

Explanation of Solution

Given information :

the linear fuction $m=55-8.5b$ represents the amount of money left after buying the books.

Hence we determine the domain of the function.

Now we know b number of books can be bought from the given amount.

Hence we get,

  $\begin{array}{l}55-8.5b\ge 0\\ 55\ge 8.5b\\ 6.47\ge b\end{array}$

We know that b cannot take the negative values.

Nearest whole number is 6 hence the domain is,

{1, 2, 3, 4, 5, 6}

Books are countable and cannot take any value between whole numbers, hence the function is a discrete function.

b.

To determine

To graph the function using its domain.

Explanation of Solution

Now we shall determine the points using the domain.

Put $b=0$ we get, $m=55$

Put $b=1$ , we get, $m=46.5$

Put $b=2$ , we get, $m=38$

Put $b=6$ , we get, $m=4$

Now let us plot the points and then join, we get,