Question

The table shows the outputs y for different inputs x:

Input
(x) 2 4 6 8
Output
(y) 1 2 3 4


Part A: Do the data in this table represent a function? Justify your answer.
Part B: Compare the data in the table with the relation f(x) = 3x – 10. Which relation has a greater value when x = 8?
Part C: Using the relation in Part B, what is the value of x if f(x) = 80?

Answer 1

A: Yes because for each x value, there is only one corresponding y value.
B: For the first relation, y is half of x, so f(x)=x/2. If x is 8, y is 4.
Plug in the value of x for the second function. 3(8)-10=24-10=14.
The second relation has a greater value.
C: 80=3x-10,
90=3x
x=30