Light waves, for which the electric field is given by Ey$($x$,$t$)=$Emaxsin$[(1\mathrm{.}40107$m$1)$x$$t$]$Ey$($x$,$t$)=$Emaxsin$[(1\mathrm{.}40107$m$1)$x$$t$],$ pass through a slit and produce the first dark bands at $28\mathrm{.}628\mathrm{.}6$ from the center of the diffraction pattern.

What is the frequency of this light?