Question

The table below shows the values of y for each value of x.

x y
0 1
1 2
2 3
3 3

Part A: Does the table represent a relation that is a function? Justify your answer by using the values shown in the table. (4 points)

Part B: The function f(h) shown below represents a plumber's total charges, inclusive of call out charges, for h hours of work.

f(h) = 70h + 50

Calculate and interpret the meaning of f(2). (4 points)

Part C: Write an ordered pair to represent the input and output of the function in Part B when the plumber works for d hours. (2 points)

Answer 1

@hoblos

Answer 2

@Hero

Answer 3

Part A is tricky. For an ordered pair to be a function, Every x must point to a unique y.

In other words, for example, we are allowed to have (1, 2), (2, 2), (3, 4), (4, 4),

But we are not allowed to have (1, 2), (1, 3), (2, 4), (2, 5)

Answer 4

So the table is a function?

Answer 5

Yes, correct.

Answer 6

Can you help me with part 2?

Answer 7

Okay, so they already mentioned that:

h = hours of work
f(h) = plummer's total charges given h hours of work

Answer 8

To find f(2) simply plug in 2 everywhere you see h in the formula:


f(h) = 70h + 50
f(2) = 70(2) + 50

Answer 9

so f(2) = 190?

Answer 10

Yes, and what you would say is

f(2) means The plummer charges $190 for 2 hours of work.

Answer 11

Oh! ok :).
What about Part C? I'm really confused about that one.

Answer 12

Part C is designed to be potentially confusing. Basically, all they want you to do is take the 2 and the 190 you found and write it as an ordered pair:
(h, f(h)) = (2, 190)

Answer 13

oh. I thought it was supposed to be (d,f(d)).
THANKS :)

Answer 14

Actually, that might be what they want. (d, f(d))

Answer 15

So which one do I use?

Answer 16

Go with your intuition, (d, f(d))

Answer 17

Ok :)
Thanks :) <3