A-1 Equipment Rental Company charges [tex]$\$195$[/tex] per day to rent a backhoe. The rental cost at A-1 can be represented by the function [tex]$a(x) = 195x[tex]$[/tex], where [tex]$[/tex]x$[/tex] is the number of days the backhoe is rented. A competitor charges [tex]$\[tex]$150$[/tex][/tex] per day plus an extra [tex]$\$90$[/tex] fee. The cost at the competitor can be represented by the function [tex]$c(x) = 150x + 90[tex]$[/tex], where [tex]$[/tex]x$[/tex] is the number of days the backhoe is rented.

Describe the transformation from the graph of [tex]$a$[/tex] to the graph of [tex]$c$[/tex]:

A. Horizontal stretch by [tex]\frac{13}{10}[/tex] and then a vertical translation 90 units up

B. Vertical shrink by [tex]\frac{10}{13}[/tex] and then a vertical translation 90 units down

C. Vertical shrink by [tex]\frac{10}{13}[/tex] and then a vertical translation 90 units up

D. Vertical stretch by [tex]\frac{10}{13}[/tex] and then a vertical translation 90 units up



Answer :

To solve this problem, we need to understand how to transform the function [tex]\( a(x) = 195x \)[/tex] into the function [tex]\( c(x) = 150x + 90 \)[/tex]. These transformations involve changes in both the rate of change (slope) and the constant (y-intercept).

1. Comparing the slopes:
- The slope of [tex]\( a(x) = 195x \)[/tex] is 195.
- The slope of [tex]\( c(x) = 150x + 90 \)[/tex] is 150.

To convert the slope of 195 to 150, we can write the transformed slope as a fraction:
[tex]\[ \frac{150}{195} = \frac{10}{13} \][/tex]
This means that [tex]\( a(x) \)[/tex] is transformed by multiplying the input by [tex]\( \frac{10}{13} \)[/tex], resulting in a vertical shrink by a factor of [tex]\( \frac{10}{13} \)[/tex].

2. Considering the constant term:
- The function [tex]\( a(x) \)[/tex] has a y-intercept of 0 (i.e., it passes through the origin).
- The function [tex]\( c(x) \)[/tex] has a y-intercept of 90.

Additionally, there is an extra amount added to the function, indicating a vertical translation of 90 units upward.

By combining these two transformations, we need to shrink the graph vertically by a factor of [tex]\( \frac{10}{13} \)[/tex] and then shift it up by 90 units.

Hence, the correct transformation from [tex]\( a(x) \)[/tex] to [tex]\( c(x) \)[/tex] is a vertical shrink by [tex]\( \frac{10}{13} \)[/tex] and then a vertical translation 90 units up.

This confirms that the correct answer is:
- vertical shrink by [tex]\( \frac{10}{13} \)[/tex]
- and then a vertical translation 90 units up.