Question

help please!

The table below shows the square roots of different numbers:


Number
(x) 4 4 9 9
Square root
(y) 2 -2 3 -3


Part A: Does the table represent y as a function of x? Justify your answer. (5 points)

Part B: The total cost f(x), in dollars, for renting a car for a week and driving it x miles is shown below:

f(x) = 90 + 0.11x

What is the value of f(300), and what does f(300) represent? (5 points)

Answer 1

hint:
the point x=4 has two images, namely +2 and -2, similarly for point x=9
what can you conclude?

Answer 2

it is not a function?

Answer 3

correct!

Answer 4

oh so that would be the answer to part a!? thats so much simpler than i thought

Answer 5

now i don't understand where f(300) comes into play?

Answer 6

yes! since your function, doesn't check the general definition of a function

Answer 7

it is simple, we have to replace x with 300, so we have to compute this:
\[\Large f\left( {300} \right) = 90 + 0.11 \cdot 300 = ...?\]

Answer 8

oh so that would equal 123?

Answer 9

correct!

Answer 10

but what does it represent?

Answer 11

it is represent the image of the point x=300, by means of your function:

Answer 12

oops..it represents...

Answer 13

ooh i think i see, alright thank you so much for your help! @Michele_Laino

Answer 14

:)