  We analyze the eccentric response of a low mass coplanar circumbinary disc to
secular tidal forcing by a Keplerian eccentric orbit central binary. The disc
acquires a forced eccentricity whose magnitude depends on the properties of the
binary and disc. The largest eccentricities occur when there is a global
apsidal resonance in the disc. The driving frequency by the binary is its
apsidal frequency that is equal to zero. A global resonance occurs when the
disc properties permit the existence of a zero apsidal frequency free eccentric
mode. Resonances occur for different free eccentric modes that differ in the
number of radial nodes. For a disc not at resonance, the eccentricity
distribution has somewhat similar form to the eccentricity distributions in
discs at resonance that have the closest matching disc aspect ratios. For
higher disc aspect ratios, the forced eccentricity distribution in a 2D disc is
similar to that of the fundamental free mode. The forced eccentricity
distribution in a 3D disc is similar to that of higher order free modes, not
the fundamental mode, unless the disc is very cool. For parameters close to
resonance, large phase shifts occur between the disc and binary eccentricities
that are locked in phase. Forced eccentricity may play an important role in the
evolution of circumbinary discs and their central binaries.
