The logistic equation The logistic equation is the differential equation
where is the dependent variable and are positive constants.
The logistic equation can be used to model population growth, where signifies the number of individuals in a population at time . The idea is that for a small population () the growth rate is roughly proportional to , but as increases then competition for resources slows the growth rate (or increases the death rate), i.e. as tends towards then the factor tends to zero, reducing the growth rate towards zero.