$15\mathrm{.}6\mathrm{.}31$ Find an equation of the plane tangent to the following surface at the given point. cos$($xyz$)=(\backslash$sqrt$(3))/(2)$;$(1,\backslash$pi $,(1)/(6))$ Determine an equation of the plane tangent to the surface cos$($xyz$)=(\backslash$sqrt$(3))/(2)$ at $(1,\backslash$pi $,(1)/(6))\backslash$pi as needed.x$+$y$+$z$=$ B$.6\backslash$pi x$+$y$+\backslash$pi z$=$ C$.\backslash$pi x$+$y$+6\backslash$pi z$=$ D$.$ x$+(\backslash$sqrt$(3))/(2)$y$+(1)/(6)$z$=$