Consider a sound wave modeled with the equations$($x$,$t$)=4\mathrm{.}00$nms$($x$,$t$)=4\mathrm{.}00$nm

cos$(3\mathrm{.}66$m$1$x$1256$s$1$t$).$cos$(3\mathrm{.}66$m$1$x$1256$s$1$t$).$ What is the maximum displacement, the wavelength, the frequency, and the speed of the sound wave?