high school algebra

Question

Under what conditions does the equation A=P*e^rt model continuos decay

Answer 1

The exponent must be negative to represent decay.  If it is positive, it represents growth.  Continuous decay would be:

 

A(t) = A₀e^-rt

 

A(t) = amount present or level at time t after t = 0

A₀ = initial amount or level at time t = 0

r = decay rate, which is a positive number, and hence the negative sign must be introduced