Almost Periodic Solutions of Equation $[\dot x = {x^3} + \lambda g(t)x + \mu f(t)\]$ and Their Stability

By using the Liapunov function and the contraction mapping principle, the author investigates the existence and stability of almost periodic solutions of the first order nonlinear equations $\frac{dx}{dt}=-h_1(x)+h_2(x)g(t)+f(t)$ and $\frac{dx}{dt}=r(t)x^n+\lambdag(t)x+\muf(t)$, where r(t), g(t), f(t) are given almost periodic functions, n(\geq 2) integer, and \lambda,\mu real parameters.