We report measurements of the momentum dependence of die superconducting gap in Bi2Sr2CaCu2O8+x with angle-resolved photoemission spectroscopy using a dense sampling of the Brillouin zone in the vicinity of the Fermi surface. In the Y quadrant of the zone, where there are no complications from ghost bands caused by the superlattice, we find a gap function consistent within error bats to the form cos(k(x))-cos(k(y)) expected for a d-wave order parameter. Similar results are found in the X quadrant with the photon polarization chosen to enhance main band emission over that due to ghost bands.