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)
Responses

exponential decay function
exponential decay function

quadratic function
quadratic function

exponential growth function
exponential growth function

linear function

Answer 1

Quadratic function.

Reason: the values are symmetric about x = 2 with a minimum y = 2 at x = 2, so y = a(x−2)^2 + 2 fits. Using (1,6.3): a + 2 = 6.3 → a = 4.3, so y = 4.3(x−2)^2 + 2, which matches all the points.