Positive Periodic Solutions of Nonlinear First‐Order Functional Difference Equations

We consider the existence, multiplicity, and nonexistence of positive T-periodic solutions for the difference equations Δx(n)=a(n)g(x(n))x(n)-λb(n)f(x(n-τ(n))), and Δx(n)+a(n)g(x(n))x(n)=λb(n)f(x(n-τ(n))), where a,b:ℤ→[0,∞) are T-periodic, τ:ℤ→ℤ is T-periodic