R icker equation In the logistic difference equation the factor s1 2 xtd decreases linearly from 1 to 0 as xt increases from 0 to 1. If, instead, we introduce the decreasing exponential factor e2xt, we get what is called the Ricker difference equation:

xt11 − cxte2xt This model has the advantage that the factor e2xt never reaches 0.

(a) If x0 − 0.5 and c − 2.5, calculate the first ten terms to four decimal places and graph them.

(b) Compare with Exercise 28.