A rental car company offers two rental plans, Plan A and Plan B, for the same economy size car. For both plans, the total rental cost f
(
m
)
is a function of the number of miles
m
that the car is driven.

Plan A:
f
(
m
)
=
0.12
m
+
75

Plan B:
f
(
m
)
=
0.35
m

I. In complete sentences, translate each function into a verbal model describing the total cost of the rental in terms of the number of miles that the car is driven.

II. For each function, determine how the rate of change will affect the total cost of a car rental.

III. For a car rental that will include a maximum of 250 miles for the duration of the rental, which plan is the most cost effective?

The rate of decay of a radioactive substance depends upon the amount present initially. the mass y (mg) of the radioactive substance cobalt-60 present in a sample at time t (years) is represented by the exponential equation y=50e −0.1315 t . answer the following questions in complete sentences. 1. how does the exponential equation above compare to the equation for simple interest that is compounded continuously? explain the similarities. 2. what is the initial amount of cobalt-60 in the sample? 2. how much cobalt-60 is left after 8.4 years? show your work. 3. what would be the y-intercept of the graph? what does it represent? 4. after how many years will the amount of cobalt-60 left be 6.25 mg? explain what happens to the cobalt-60 after 50 years? 5. discuss some “real-world” examples and uses of cobalt-60

If f(x)=3x+1 and f^-1=x-1/3, then f^-1(7)=

What is the slope of the equation y =