function dydt = lvrhs(t, y, alpha, beta)
% Derivatives of Lotka-Volterra equations with parameters alpha and beta.
% y and dydt are 2x1 vectors.

dydt = zeros(2, 1);
dydt(1) = (1 - alpha*y(2))*y(1);
dydt(2) = (-1 + beta*y(1))*y(2);
