Chapter 17.3, Problem 9E

Suppose a spring has mass m and spring constant k and let $\omega =\sqrt{k/m}$. Suppose that the damping constant is so small that the damping force is negligible. If an external force F(t) = F₀ cos ω₀t is applied, where ω₀ ≠ ω, use the method of undetermined coefficients to show that the motion of the mass is described by Equation 6.