Answer:
a) y = 400(0.75) ^x
b) Exponential Decay
Step-by-step explanation:
An adult can take 400 mg of ibuprofen. Each hour, the amount of ibuprofen decreases by 25%.
a. Write an equation of this exponential situation for the total amount of ibuprofen, y, in terms of the number of hours, x.
This situation above is an exponential decay situation.
The forms is given as
y = a(1 - r) ^x
Where
y = the total amount of ibuprofen
a = initial amount of ibuprofen = 400mg
r = Decay rate = 25%
x = Time in hours
Hence, the Equation is written as
y = 400(1 - 0.25) ^x
y = 400(0.75)^x
b. Does this situation represent exponential growth or decay? Explain how you know
This situation represents an exponential decay because we are told in the question that each hour, the amount of ibuprofen DECREASES by 25%. Decrease in this context means Decay.
