Question

The table below shows the cube roots of different numbers

Number(x) 8 27 64 125
Cube root(y) 2 3 4 5

Part A: Does the table represent y as a function of x? Justify your answer.
Part B: The total cost f(x), in dollars, for renting a bike for x hours is shown below:

f(x) = 10 + 20x

What is the value of f(100), and what does f(100) represent?

Answer 1

Part A : Yes, it represents y as a function of x. There are not 2 different y values for the same x value.
f ( x ) = ∛ x ( or : y = ∛x )
Part B : f ( x ) = 10 + 20 x
f ( 100 ) = 10 + 20 · 100 = 10 + 2,000 = 2,010
f ( 100 ) represents the total cost for renting a bike for 100 hours.