(a) Does a function of the form u(t) = cos t - b cos ...

Question:

(a) Does a function of the form u(t) = α cos η t - b cos ω t still exhibit beats when η ≈ ω, but
α ≠ b? Use a computer to graph some particular cases and discuss what you observe.
(b) Explain to what extent the conclusions based on (9.98) do not depend upon the choice of initial conditions (9.97).