Question

The table below shows the squares of different numbers:

Number 2 -2 3 -3
(x)
Square of the number 4 4 9 9
(y)

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 rowboat for x hours is shown below:

f(x) = 20 + 3x

What is the value of f(150), and what does f(150) represent? (5 points)

Answer 1

The table in Part A represents y as a function of x. This means that the value of Y is dependent on the value of X. The table can be represented by an equation that describes the relation of X and Y:

`y = x^(2)` or
`f(x) = x^(2)`
By substituting any value of X, you get a specific value of Y based from the given relationship, thus Y is a function of X.

For Part B, the value of f(150) is $470 and it represents the total cost for borrowing a rowboat for 150 hours. By substituting the value of x = 150 into the function, you get the total cost:

`f(x) = 20 + 3x \\ where \\ x = 150 \\ f(150) = 20 + 3(150) \\ f(150) =20 + 450 \\ f(150) = $ 470`