Craig bought a treadmill for $400. he estimates that the annual costs to maintain the machine will be $36. which rational function yields the average annual cost in dollars of owning the treadmill for x years?

Given that Craig bought a treadmill for 400 dollars.

Useful life of the macine = x

Hence annual purchase cost spread over x years will be 400/x per year.

In addition, there is an annual maintenance cost of 36 dollars.

Hence Average annual cost in dollars = purchase cost per year+maintenance cost per year

=

Hence answer for rational function is

either

let's cover over the formula of the vertex:

y = a(x – h)^2 + k

in this formula, (h,k) are the vertex, always remember that the positive or negative value of the vertex is based on the sign it has.

for example, if the vertex is -3,-6 then both the x and y value would have the positive sign attached to it and if it were a positive x and y value, then a negative sign would be attached to it.

with that being said, for our problem the x value is a positive one so we are looking for a number with a negative sign next to it, in this case the first and second choice.

however, for the first answer choice it isn't quite part of the formula so we know that the answer choice correctly displays the x value.

to confirm, we can see if the -1 fits correctly with the second answer choice, and as mentioned above a negative number will have a positive sign attached to it. so, for our problem we can see that -1 has been changed to +1, so we can confirm that the second answer choice is correct.

hence, our final answer is y=(x - 1)^2 + 1