Question

In class, Julie was asked to create a scenario for the linear function shown. She came up with the following: .Joe planned a hiking trip from where he parked his car to the mountain cabin he had rented. Joe parked 12 miles away from the cabin. After one hour, he was still 7 miles from the cabin. Joe’s hike from his car to the cabin can be modeled by the function f(x)=-3x+12. Does Julie’s scenario match the linear function graphed? If not, where does she go wrong? How can she correct her mistake and match scenario to the function?

Answer 1

Answer:

1. Julie’s scenario doesn't match the linear function graphed, because the graphed function is f(x)=-3x+12 and must be f(x)=-5x+12

2. She has counted the slope of the line incorrect.

3. She can write f(x)=-5x+12 and draw the line with the x-intercept will be at (2.4,0) and y-intercpt ar (0,12).

Step-by-step explanation:

If Joe parked 12 miles away from the cabin and after one hour, he was still 7 miles from the cabin, then he had walked 12 - 7 = 5 miles per hour.

The initial positon of Joe is at point (0,12) (after 0 hours passed, Joe was 12 miles from the cabin). The line must pas through the point (1,7) ( after one hour, he was still 7 miles from the cabin ).

Find the slope:

$\dfrac{y_2-y_1}{x_2-x_1}=\dfrac{7-12}{1-0}=-5$

So, the slope of the linear function should be -5 (not -3).

Then the equation of the function is

$f(x)=-5x+12$

1. Julie’s scenario doesn't match the linear function graphed, because the graphed function is f(x)=-3x+12 and must be f(x)=-5x+12

2. She has counted the slope of the line incorrect.

3. She can write f(x)=-5x+12 and draw the line with the x-intercept will be at (2.4,0) and y-intercpt ar (0,12).