New results of periodic solutions for forced Rayleigh-type equations

In this paper, we use the coincidence degree theory to establish new results on the existence and uniqueness of TT-periodic solutions for a kind of forced Rayleigh equation of the form x″+f(t,x′(t))+g(t,x(t))=e(t).x″+f(t,x′(t))+g(t,x(t))=e(t).