Create an explicit exponential equation to model the change in quantity of pesticide present in the soil over time.

Question

The amount of a particular pesticide in soil decreases by 1.15% per day after application. A homeowner applies 68 grams of the pesticide to a square yard section of lawn.

 Create an explicit exponential equation to model the change in quantity of pesticide present in the soil over time.

P_{n = __________}

Answer 1

In general P(n) = P(o)(1+r)^n

where P(o) is the initial amount which in this case is 68 grams

r is the rate of increase or growth which in this case is 1.15% or 0.0115 (for decay we would make it 1-r)

n is the number of days which have passed

P(n) = 68(1.0115)^n