Describing Domain and Range

Customers pay $$ 20$ for the full cleaning of the car. Changing of tires can be purchased selectively for $$ 10$ per tire. The variable $x$ represents the number of tires changed, which can be from no tire up to all four. The domain is then the set: $D : {0, 1, 2, 3, 4},$ where the values show the number of tires the customer decides to change. To find the range we calculate the corresponding function value for each of the values in the domain.

$x$	$20 + 10 x$	$y$
$0$	$20 + 10 \cdot 0$	$20$
$1$	$20 + 10 \cdot 1$	$30$
$2$	$20 + 10 \cdot 2$	$40$
$3$	$20 + 10 \cdot 3$	$50$
$4$	$20 + 10 \cdot 4$	$60$

We have now found the range of the function. $R : {20, 30, 40, 50, 60}$ Let's plot the points on a coordinate plane to have a graph of the function.

Describing Domain and Range 1.6 - Solution