Question

The value, y, in USD of a particular stock for 4 days, x, is shown in the table.

USD of Particular Stakes
days 0 1 2 3 4
stock value ($)
19.2 6.3 2 6.3 19.2
What type of function could be used to model the value, y, of the stock as a function of time, x?

(1 point)

linear function

exponential decay function

exponential growth function

quadratic function

Answer 1

Quadratic function.

The values are symmetric about x = 2 with a minimum at (2, 2), so they fit a parabola. For example,
y = 4.3(x − 2)^2 + 2
gives y = 19.2, 6.3, 2, 6.3, 19.2 for x = 0,1,2,3,4.