Marginalised constraints (1σ contours) on the dark energy equation of state parameters for the DESI-like (solid lines) and for the Euclid-like (dashed lines) surveys, assuming 20 tomographic Gaussian bins of σ_z = 0.01. The blue lines are the constraints for angular galaxy clustering alone, the orange lines are for ARF alone, and the green lines are a joint analysis of both fields, D_g,  z. These contours are marginalised over the set of cosmological parameters as before, and over the galaxy bias in the 20 redshift bins. We display the figure of merit (FoM) of this pair of parameters in the upper right box for each combination of observables and for each survey.